ARCHIVAL THEORY AND PRACTICE
Lecture notes by Todd Ellison. Copyright Todd Ellison 2015. Permission is granted for use, but not for sale or any commercial or monetary gain, and you must link to this website.

7th section of this course
#7

XIV.  Archival preservation  

If you hope to preserve for posterity
something treasured or thought to be verity,
you'd better learn fast
how 'twas made in the past
and act now with forethought and clarity.  

Do no harm: a basic preservation key to managing archival collections


A note from an exhibit at the Anasazi Heritage Center near Dolores, Colorado, May 1992:

"In a world of created objects, some things are special to us.
They remind us of who we are, where we came from, how we have changed.
We delight in their presence and grieve at their loss."

              and

"Nothing lasts forever...  But skill and attention can help a few things last a very long time."


A.  The nature of library and archival materials

1.  three classes of library materials: (per Paul Banks of Columbia Univ.)

       a.  rare collections - artifactual value - artistic, historic, or intrinsically significant

       b.  general collections

        (1) important for info content primarily

        (2) e.g.  an unabridged Webster's dictionary

       c.  research collections

        (1) lies between the first 2 classes

        (2) permanent research value, with potential value as artifacts

2.  solutions for 1 class of materials may not be appropriate for the others

       a.  treat paperback books (class 2) differently from illuminated MSS (class 1)

       b.  difficulty is predicting the fate of those in class 3, which includes most archival materials
 

B.  Working definition of preservation: (from the 1985 statement of the Committee on Research Library Materials) "a coordinated set of activities associated with maintaining library and archival materials for use, either in their original form or by converting to another usable medium, to provide protection for and continued availability of use of these documents." (def.  is in class's glossary)

1.  inherent in this definition is the concept of information preservation, either through reformatting or purchasing microform, etc.

2.  traditionally, east coast people use the term preservation, west coast calls this conservation; but preservation is the umbrella term

3.  conservation = the use of physical or chemical treatments to stabilize and thus to extend the useful life of documents; includes the decisions of which materials should receive treatments

       a.  thus, in the U.S.  usage, preservation is the umbrella term for all activities aimed at eliminating or minimizing the harmful effects of the environ­ment surrounding an object and of the inherent vice within an object

       b.  conservation is a more specialized term for such preservation activities as repairs and stabilization of items

       c.  restoration is a third term, referring to returning an item to a condition somewhat close to its original state


C.  Motivations for archival preservation

1.  costs (as of 1985)

       a.  $2,000 for a signed printed one-page letter of Simon Bolivar

       b.  $50,000 for an 8-page document by Pizarro

       c.  $15,000 for a 1/4 page autographed letter signed by Titian in ca.  1595

       d.  a typical Hollinger box of MSS is probably worth about $200-$300

2.  nearly all materials will deteriorate over time - some, more quickly than others

       a.  cf.  article "Riddle of the Archives" stating that half of all films made before 1950 have turned to dust on the shelves

       b.  American Archivist on nature of "permanence", and 2 more definitions

        (1)  permanence = the stability of an item's chemical properties, e.g.  the degree to which paper withstands impurities in its chemical composition; it's permanent if it retains its original chemical form indefinitely

        (2)  durability = the physical properties of the material, i.e.  how much physical strength it retains through use


D.  Factors that have impact on the conditions of documents:

1.  factors inherent in the materials themselves

       a.  inherent instability from historical factors

        (1) built in from the moment of production

        (2) internal causes of deterioration within the constituent materials (3) "inherent vice"

       b.  paper as a case study and prime historical example of inherent vice

        (1) the Aug.  1990 Abbey Newsletter picked up the following 100-year-old reprint from the June 1990/1890 issue of Scientific American: "'Visitors to the British Museum frequently have a hard time getting "acclimated" to the place.  An hour spent in the rooms invariably gives the first-time visitor a headache.  This curious malady is said to arise from the peculiar odor created by the storage of so many books.  You can get some idea of what this odor is by going to your book case, that has been closed for 24 hours, and opening one of the doors; immediately your olfactories will be greeted by the mustiest fragrance imaginable.  Bibliomaniacs profess to love this odor, and many declare that they cannot value a book unless it has about it that unmistakable and ineradicable smell which infects a volume when once it has crossed the sea in the hold of a vessel.'"  McCrady, editor of the newsletter, comments that  "one component of that fragrance had to be the gases given off by deteriorating paper made with groundwood pulp, which had been used in increasing quantities in books for the previous 30 years."  Our study of the composition of paper over the year will add to your appreciation of "that delightful smell of moldy books," and will serve as an introduction to the challeng­es of archival preservation.

        (2)  paper is an organic material made by bonding fibers - slender, thread-like filaments usually composed of vegetable elements; cellulose, the predominant element, is a polymer, a crystal, a long-chain molecule composed of up to 5,000 monomer units; close packing of these cellulose chains is important in paper making

               (a) cellulose is a long fibrous molecule

               (b) cellulose is a component of the stems and seeds of plants

               (c) the strength of a piece of paper is determined by the length of the cellulose fibers of which it is composed; the longer the fibers, the stronger the paper

               (d) the deterioration of paper is the result of the breaking up of the cellulose fibers during its manufacture, its use, and its storage

       c.  history of papermaking

        (1) the first paper - handmade:

               (a) its origins

                     i) it is commonly accepted that the Chinese invented paper in about 200 A.D.

                     ii) knowledge of this invention arrived in Europe a thousand years later

                     iii) its use soon became widespread because it was less expensive to produce than parchment

        (b) how it was made:

              i) early European paper was much stronger than most paper made today, because it was made from the cellulose contained in linen and (scarcer then) cotton rags, which underwent very little chemical and mechanical processing in the early days of European paper making

              ii) sorted by hand into troughs, washed, rolled into balls and soaked/rotted ("retting"), cooked in water (later on, in lime), beat (originally, in 12th century, in water-driven stamp­ers) and gently macerated (by a rough stamp with iron teeth to rend the fabric, by a rough stamp to make pulp, and by smooth wood to make fine pulp), then stirred, molded, rolled into sheets, pressed and line dried

              iii) this process altered the fibers' dimensions and surface characteristics; fibers would swell with the water and the fiber network would be frayed which would increase the surface area and allow better inter-fiber bonding; the process also would shorten the fibers--if too long, they would clump up in the pulp

              iv) more on the sheet forming process: poured out the watery slurry into a wooden vat, using a paper mold which had cross-ribs (creating laid lines and chain lines), then placed a wooden fence-deckle over the mold to keep the slurry on the mold (usually 2 molds fit in 1 deckle), then the vatman would  plunge the mold vertically into a vat and pull it out horizontally, giving it a 4-way shake; 2nd worker, the coucher, did the next part, picking up the mold vertically and turning it over, transferring the west sheet to felt, working harmoniously with the vatman until a post (about 144 sheets) was accumulat­ed; then, squeezed the post in a screw press, reducing its thickness from 24" to 6" as excess water is expelled; third worker, the layman, then would separate the sheets from the felts and press the sheets, then take them up to the drying loft at the top of the paper mill where they were hung over ropes in groups of several sheets (if hanged individually, would wrinkle), using louvered shutters to control air flow in the loft

        (c) characteristics of early handmade paper:

              i) the original pulp (at the start of the paper making process) is 99% water

              ii) later, paper is 94% solid material and 6% water

              iii) handmade paper theoretically has no grain due to the 4-way shake

              iv) watermarks are not make by water at all, but by bending brass wires and then stitching them into the paper mold

              v) early handmade paper was more durable and permanent than subsequent paper because:

                     a) was formed from relatively pure and stable cellulose fibers

                     b) the fibers were still long, thus creating a strong sheet of paper, because there was more oppor­tunity for linkage of the fibers

              c) fibers were strongly interlinked, in every direction

              d) the raw materials used in early paper production were not acidic

(2)  shift to machine-made paper:

        (a) first paper making machine was devised in France

              i) by Nicholas Louis Robert

              ii) with the backing of his employer Leger Didot

              iii) Robert obtained the first patent in 1798

              iv) crude and simple, it produced a roll of wet paper

              v) the machine was well established by the 1830s, featuring a roll of endless length; the width was only limited by the size of the machine (previously, it could be only as wide as a man could handle)

              vi) machine-made paper has grain because it is shaken only side to side as it comes off the machine, so the paper is stronger side-wise than length-wise

        (b) in the 19th century, the "Fourdrinier" paper making machine

              i) by Henry and Sealy Fourdrinier, on the market in 1807

              ii) produced a continuous sheet of paper

              iii) wrapped it around a roll

              iv) but they still had to hand dip the paper into the animal glue, to size it

        (c) modern machines are 4x as wide and 100x as fast as the

early cylindrical ones developed by John Dickerson in the early 1800s, but are very little different in their principles of opera­tion

(3)  inherent vice introduced to the manufacture of paper:

        (a) evolution of technology led to introduction of congenital defects

        (b) change in acidity - sizing was the first problem added to the paper

              i) in about the mid 13th century, gelatin was added to the paper to give it a hard surface which would be impervious to ink bleeding; sizing fills in the spaces in the paper so that one can write on it smoothly

              ii) this is called "sizing" -it stops the feathering or blurring of the print

              iii) this gelatin was "animal glue" produced from boiled hooves, bones and hides and skins etc.

              iv) it was applied to the surface of the paper after the paper was dry so the ink wouldn't run

              v) it was soon discovered that the gelatinous sizing deteriorated rapidly - got moldy

              vi) so from about the mid-17th century, alum (potassium aluminum sulphate) was added to control the growth of bacteria and thus to prevent further decomposition of the glue - problem is, this made the glue very acidic

              vii) acid is the greatest cause of deterioration in paper

       a) the chemical reaction is called acid hydrolysis

       b) you smell the result of it when you open up an old chest of old papers in your

gran­d­mother's attic

       c) remember, paper is made of chains of cellulose

       d) acid is a proton donor; in solution, it ionizes into hydrogen ions and a base and thus attacks the bonds in the polymer chain; after just 1% of the bonds are broken, the paper is virtually useless, lacking durability

       e) thus, in acid hydrolysis, the vital links are broken and the paper become brittle

       f) {demonstrate}

       g) acidity is measured in terms of Ph, which is a scale, ranging from 1 (most acidic) to 14 (most basic or alkaline)­ of the hy­drogen-oxygen ionization in material; it's algorithmic, so a paper with a pH of 3 has 10 times as much acid as a pa­per with a pH of 4 and 100 times as much acid as a paper with a pH of five; we prefer a neutral pH of about 7, which is the pH of pure water, or a moderately alkaline range between 7 and 8

       h)  the pH of most paper is in the acidic range below five, which, unfortunately, has­tens decomposi­tion of the paper

(c) acid is like water; it migrates between adjoining papers to equalize the pH in them

(d) to determine the pH of a substance, one must first dissolve its acids in water; pH is measured on the surface using pH indicator strips (those mfd.  by E.M.  Laboratories, Inc.  are recommended; unlike most strips which run and thereby discolor the paper when moistened, these will hold their dyes) which are moistened and placed next to the paper, then compare the color they turn to a chart; pH pens or pencils also can be used, but require making a mark on paper; the most sensitive technique is an electron meter (a wand)

(e) procedure for determining pH:  you'll need distilled or deionized water, an eyedropper, two small pieces of blotting paper, a small flat piece of glass or plexiglass and the pH indicator strips.  Lay the paper on a flat, clean surface.  If the paper is thin it should be tested over a piece of glass or a sheet of mylar.  Place a drop of water on an inconspicuous spot, away from any inks.  Don't test water soluble papers such as those decorated with multi-colored inks or pastels.  In books, test both a page near the cover and an interior page.  Put the pH test strip with the colored indicator squares face down on the moistened area, then place the glass or plexiglass weight on top of the test strip. After two minutes, remove the test strip from the paper and compare it with the color key that comes with the pH test kit.  Record the pH of the paper on your examination report sheet.  If the color on the test strip is between two colors on the chart, record the value as one-half of the difference.  As soon as you remove the pH strip, place a blotter on both sides of the damp spot to absorb the moisture.  This will reduce the possibility of a water stain.  To further reduce the risk of staining, moisten the test strip instead of the paper, and only apply the edge of the strip to the paper rather than the entire width of the strip. (Jeffrey D.  Goldstein, "Determining the pH of Paper," National Park Service Conserve O Gram, Dec.  1976)

- "Acids are the villains responsible for the major portion of paper deterioration."  (Jeffrey D.  Goldstein, "Determining the pH of Paper," National Park Service Conserve O Gram, Dec.  1976)

- in 1805 a German paper maker found that he could add alum rosin sizing to the rag mixture; using another alum which introduced even more acidic damage, sulfuric acid

- with the switch to machine-made paper, the manufacturers wanted to add the sizing to the pulp, instead of unrolling the paper and cutting it into sheets first - they found a way to effect this "internal sizing" in 1807, by using rosin (the sizing agent) and alum (to make the rosin precipitate onto the pulp fibers) - by the 1830s, this process was widely used - it was a time saver and it improved the performance of the machine, because the rosin reduced foam - but the chemical reaction of rosin and alum led to an acidic product, and in their desire to make their machines run smoothly the paper makers used too much rosin - this changed when a tax on imported rosin-alum made it too expensive

- in 1876 a new alum (aluminum sulphate) - even more acidic - was manufactured using acid - this was the single most important factor in 19th century paper making - it was called "paper-maker's alum", and it was even more acidic than rosin/alum

(f)  bleaching was the second problem introduced: mills had a shortage of raw materials, and needed a means of producing white paper from colored or soiled rags

- chlorine was discovered in 1774 by Karl Scheele; this discovery was seen as a boost--could use rags hitherto unusable - could quickly bleach materials white even if they were stained; but with water it forms hydrochloric acid - very acidic

- and before it was controlled, overuse of chlorine resulted in the production of some paper that only lasted 15 years

- all these changes resulted in a higher acid content of the paper

- the paper making processes weren't standardized until the 19th century, and were poorly documented

(g)  fiber length was the third problem introduced to the manufacture of paper

- if paper is made from fibers that are too short, the paper doesn't last

- the 12th century water-powered stamper was very slow, though an improvement over the mortar and pestle, and it produced long-fibered paper

- in the mid-17th century the Hollander beater replaced the stamper; it was a cylinder that macerated rags; was faster than the stamper, but unfortunately resulted in a product which had somewhat shorter fibers, which became a problem when acidity was increased, because short fibers break up faster

- mechanized paper makers preferred the shorter fibers because they worked better in the machines

- fibers became even shorter with the use of steel blades in the Jordan refiner, a beater introduced in the mid-19th century which tore the rags in a slashing action from 2 conical plugs with metal knives in between

- any treatment subsequent to sizing is called "finishing", which might include using a glazing hammer to smooth the surface - would this also shorten fibers?

- by the mid-1800s, the multiplier effect was taking its toll

- furthermore, with demand for paper and technological advances in papermaking, the rag supply became inadequate by the mid-19th century

- pulp fiber was the answer; ground wood paper was envisioned as soon as the early 18th century; in 1719 a Frenchman suggested using wood, after observing wasps' nests; Shafer made paper out of straw, potatoes, corn husks (mid-18th century), and in 1801 Matthias Koop (English) obtained a patent for using wood and straw to make paper; Koop was the first man to use fibers directly obtained from vegetable sources in a commercial venture (though he went bankrupt after several years); other scholars or scientists experimented, but the 1774 discovery of chlorine and Eli Whitney's cotton gin in 1794 took away the impetus to find an alternative to the use of rags

- the cotton gin provided for other uses of cotton than cloth, and thus delayed the need for new raw materials for paper-making by about 50 years

- in the 1840s the production of paper from wood pulp finally became a reality, with Gottlob Keller's invention of the wood grinding machine in 1840 - by treating the pulp mechanically, changing the physical structure of the wood without using chemicals; the method caught on fast because wood was plentiful, easily handled and processed, and there was little waste (used nearly 100% of it; nothing was removed from the wood)

- but, the paper produced this way had weak fibers, clumped up and not interlocking, and acidic (due to the presence of acidic non-cellulose materials, notably lignin, which--though it gives structural strength to shrubs and trees, causes yellowing and acidification when its breakdown is hastened by exposure to light (cf.  the morning newspaper when it has been exposed to the sun for a day or two) and acidic sizing agents; thus the resultant paper was weak and unstable; between 1870 and 1880, ground wood became the primary ingredient of newsprint

(h) when making paper from wood, one can utilize 95% of the tree if keeping the lignin; if the lignin is removed, one can only use 35% of the tree (per Chloe MacDonald, Library Technician, U.S.  Geological Survey)

(i) the worst paper was produced between 1870 and 1950, with the very worst usu.  produced during wars; its quality is much better today (test with Abbey pen)

- lignin molecules are a big threat to cellulose; due to the physical structure of the lignin molecule, it has many points of possible attachment, making the stacking of cellulose polymer molecules distorted, lumpy and weak

(4) 2 types of modern day paper pulp processing:

(a) chemical

i) can result in good paper: paper made from wood need not be of poor quality; if the wood is properly refined and the non-cellulose elements like lignin are purified from it, it can produce a very good paper; the key is chemical processing to remove the damaging non-cellulose elements of the wood, esp. the lignin; function of the chemicals is to liberate and purify the fibers without breaking them; separating the cellulose fibers from the non-cellulose fibers by cooking the pulp over heat removes about 95% of the lignin, and controlled bleaching completes the process; the ingredients for high quality paper are (1) pure and stable cellulose fiber, (2) long, strong fibers, and (3) the use of non-acidic raw materials

ii) 2 types of chemical processing are alkaline and acid

a) alkaline chemical processing is the older (by 30 years) method

b) it is non-acidic

c) alkaline techniques were first developed in 1851 by Hugh Burgess using a soda process, which was used extensively in U.S.  for about 30 years

d) it involved boiling the wood chips in lye, which produced a caustic soda which cooked the wood

e) this was damaging to the fibers, making them short, soft and weak, but it could be very smooth, making a good printing cushion for photographic papers including magazines

f) in 1889 the alkaline chemical technique was improved using a sulphate process

g) underlying principles were the same as for the soda process

h) it made a very dark, strong pulp, and new bleaching technologies after 1930 weren't so damaging to the cellulose, so this process is used for the production of most chemical wood pulp

i) it yields a greater amount of stronger fiber, because the process is less damaging to the fibers

iii) acid processing methods involving sulfite processing were developed in 1867

a) wood chips were boiled in sulfurous acid, with lime acid

b) first commercial mill was in Sweden in 1874; this process was well established by the end of the 19th century and was most popular from the early 20th century to 1937

c)  water + sulphur dioxide

d) sulphurous acid + limestone

e) calcium sulphite + sulphurous acid, which resulted in calcium bisulphite which cooked the wood and removed the non-cellulose materials

f) this was a very difficult series of chemical reactions, and the acid was potentially damaging

g) but, little lignin remained and little bleaching was necessary

 (b) semi-mechanical

i) semi-mechanical processing was developed in the 1920s

ii) combination of mechanical and chemical processes

iii) cook the wood chips in mild chemicals and wash them, then separate the fibers and re-wash the pulp

iv) more chemicals were added after 1955

v) lowered expense of paper produced from wood pulp in the mid 19th century led to an increase in the dissemination of information: 2,000 new titles/year (U.S., Western world, or what?) in 1880, 13,000 new title/year by 1910

vi) people became more literate, and more people were writing, which had led to the development of the modern public library by the late 18th century (in the 1870s the American Library Association was founded and the Dewey Decimal System begun)

vii) public libraries are a product of the industrial revolution, rising in increasingly urbanized areas among people with more time and inclination to read

 

viii) mechanically produced paper, in general, is inferior to chemically produced paper

(5) alkaline sizing

(a) recognizing the importance of not introducing acids to the material

(b) alkaline sizing was pioneered by William Barrow, who did landmark studies on the problems of preservation

(c) usu.  entails use of CACO3 (calcium carbonate), like TUMs as the buffering agent

(d) non-acidic sizing entailed a costly change of papermaking facilities; this seemed hardly justifiable

(e) only 7% of the paper used for books requires it, because most paper for books goes into trade books, and paper for book publishing represents only 1% of the paper market

(f) in 1959, a sizing process was marketed that was compatible with paper manufacturing facilities

(g) first "permanent and durable paper" was produced in Dec.  1959 by Standard Paper Company

(h) numerous mills have since "gone alkaline" - notably, S.D.  Warren Company in Boston

(i) recent legislation mandating or recommending the use of pH-neutral paper for permanently valuable books and documents

(6)  summary about paper making and the quality of paper:

 

(a) pre-18th century paper was good; pulp was better, wasn't bleached, materials added to it weren't harmful, and calcium in the water retarded acidification

(b) remember:

i) just because a paper is all rag or all cellulose doesn't mean it is stable or durable; bleaching, sizing, cutting the fiber too short all can result in poor quality paper despite good raw materials

ii) wood pulp paper isn't necessarily poor; it can be good if the non-cellulose materials are removed by being chemically refined - high quality paper can be produced from either soft or hard woods,  and

iii) there's more to good paper than its being acid free

(7) trends in paper use

(a) thermal fax paper, consisting of a base paper with a thin color-forming layer on the top surface, were found to have an optimum life expectancy (if stored under optimal conditions) of only 5 years; if the data on this paper will be needed for longer than that, the fax should be photocopied onto acid-free paper and the fax discarded.  (Source: Abbey Newsletter, Dec.  1989)

(b) the New York Times (Dec.  13, 1988) had an article about the possible future use of an ancient African plant, kenaf, which could prove to be a better source of pulp for paper.  It's a fast-growing plant that looks like sugar cane; a mill in McAllen Texas is considering making paper out of it.  The advantages of this fiber highlight what one seeks in archival paper: it is stable (is said not to yellow) and has good tear strength (which is difficult to achieve in modern alkaline papers).  Also, it has minimal impact on the environment (unlike wood, kenaf can be pulped with heat and pressure using only minor chemical treatment, and it wood save trees).  The U.S.  Dept.  of Agriculture has selected it as the most promising source of pulp to supplement wood; newspapers of the future may be printed on kenaf!

(8) summary: paper is a live thing, like a little animal; without oxygen and without water, it will crumble (how does paper fare in a time capsule, then??)

d.  ink

(1)  basic formulation

(a) finely powdered coloring material (pigment or dye)

(b) fluid component as the vehicle or medium (water or oil)

(c) thickening agent, used at times to keep coloring material in suspension or to give ink proper "body"

(2) carbon inks

(a) history

i) (per Chloe MacDonald) invented 2,500 B.C.  in China

ii) used since 11th Dynasty, Egypt, to 7th century A.D.; still used in West until the 19th Century

(b) carbon ink mfg.  procedure

i) burn pine rosin to produce soot which is formed into sticks

a) burn organic materials

b) products of combustion are carbon and resinous compounds

c) grades of carbon depend on resinous impurities

   ii) the Chinese brushed it onto their soft Chinese paper which had a non-gelatinous sizing, with great success

(c) formulation

i) mix carbon and water

ii) thickening agent (gum arabic) added to prevent carbon settling out

(d) characteristics: carbon ink is the best

i) very stable when pure; permanent

ii) not corrosive to paper; safely bonds to paper

iii) soluble in water (gum arabic)

(3) "iron gall" inks

(a) history

i) used from at least the 7th century A.D., into 20th century

ii) invented for use on parchment or vellum

(b) major constituents

i) ferrous sulphate

ii) iron pyrites (fool's gold)

iii) often, residual sulfuric acid from production

iv) gallic and tannic acids - aqueous infusion of tree galls

v) gum arabic added to the early inks to add body so ink flows from quill pens

(c) formulation

i) made from oak galls (the balls on oak trees) steeped in water

ii) ferrous sulphate (iron filings) was added to the infusion of galls, then the mixture was strained and gum arabic was added

iii) when freshly prepared, colorless

iv) exposure to air results in oxidation

a) colorless, soluble ferrous gallotannate compound converts to dark, insoluble ferric gallotannate compound--turns reddish brown (rusty)

b) sulfuric acid is formed during this chemical reaction

(d) historical background

i) 18th century experiments to impart color to fresh ink using logwood (hoematoxylin)

ii) oxidation of ink exposed to air in container, and precipitation and sedimenta­tion

a) addition of free acids to inhibit oxidation and control precipitation

b) partial oxidation of ink (for color), then addition of acids (to control precipitation)

(e) variation in color

i) liquid ink: if too viscous or too thin, ferrous and ferric compounds precipitate out, deposit as black sediment, and liquid ink pales

ii) on written manuscripts

a) inks made with excess ferrous sulphate faded

b) inks made with greater ratio of tannic and gallic acids to ferrous sulphate remained black, but were more acidic and could "corrode" paper

(f) damage to paper

i) acid deterioration

a) residual acid in ferrous sulphate

b) imbalance of primary components (see (d) ii) b) above)

ii) influences on destructive action

a) composition of paper

b) conditions under which paper was stored

c) concentration of ink

(4) synthetic aniline dyes (used 1856 on)

(a) coal tar dyes, 1856

i) coal tar

a) byproduct of manufacture of coke and coal gas

b) distillation products of coal tar can be synthesized into dyes

(5) modern inks, esp. ball point pen ink

(a) early inks (post World War II) - oil vehicle mixed with dye

(b) later inks - mixtures of water and wetting agents, water soluble dyes or dispersible pigments, penetrating solvent to quicken the drying time

(c) same basic formula as iron gall ink, but with synthetic dyes, using sulphuric and hydrochloric acids to keep the pigments in suspension

(d) very acidic; smears (if oil based, which is often the case); fades; lies on the surface of the paper

(e) what to use?

i) India ink (really, Chinese ink)

ii) pencil (this gives us new respect for this humble instrument)

iii) Abbey Newsletter (Feb.  1991, p. 4) mentions a Sakura Gelly Roll, XPGB, made in Japan, advertised as permanent, "`gel ink technology; pigmented, waterbased ink for permanent writing; waterproof, fade-resistant and chemical-proof; no drips or smears; uses 100% of the ink'," uses a rolling ball, not felt tip, and "gives a very smooth line," writes Ellen McCready, "at least while new.  And it costs only 89 cents."

e.  photographs have special types of inherent vice

- nitrate negative film is unstable and should be segregated from all other materials

- color photos and slides are unstable, though not dangerous

2.  factors external to the materials:

a.  environmental factors and their effect on constituent materials

(1)  temperature - heat from sunlight, heating systems, & artificial lighting accelerates all chemical processes; it has traditionally been said that for every 10 degrees Celsius temperature increase, you double the rate of chemical deterioration in paper; an article by a Smithsonian Institution research chemist in the June 1989 Abbey Newsletter says this is a myth, part of conservation folklore.  David Erhardt writes, "as with most myths, the doubling-every-10°C statement does have a grounding in fact.  Chemical reactions are of course sensitive to temperature...  The sensitivity of reaction rates to temperature is not, however, linear or the same for all reactions, but is an exponential function of both the temperature and the activation energy of the reaction.  ...  The reactions of cellulose...tend to have high activation energies...  This is equivalent to doubling in rate about every 5°C! ...  These numbers have interesting consequences.  Using the old value of reaction rates doubling every 10°C, a library which wanted to double the life of its collections would have to reduce its temperature from 75°F...to 57°F, which is not very practical.  ...(...A change of 10°C is equal to a change of 18°F.)  However, using the more justifiable 5°C value, the temperature would only have to be lowered to 66°F, which is cool but not unendurable.)"

- high heat can desiccate, embrittle, melt, and scorch items

- optimum temperature is as cool as possible, taking into account human comfort, condensation when taking items from cool to warm areas, and air conditioning expense; about 65 degrees is best

- temperature should be a top priority when specifications for archival storage are considered

(2)  relative humidity - has a symbiotic relationship with temperature

(a) physical damage:

i) hygroscopic materials such as paper have the ability to absorb and give off water; paper expands when wet, whereas cloth contracts; the two materials expand and contract in opposition to one another; this causes problems with objects composed of different materials

 ii) high r/h can increase insect activity

iii) at about 40% r/h and below, cellulose materials begin to dry out--desiccate--and the sheet weakens as fibers break--so low r/h is also a problem

(b) chemical damage:

i) moisture is necessary for some chemical reactions (esp. red rot on leather and hairy mold--at over 60% r/h, the ever-present mold spores are activated, esp. on organic material) and foxing of paper containing iron pyrite), and high r/h intensifies the effects of air pollution and acid hydrolysis

ii) above 60% r/h, the gelatin layer of photos can begin to liquefy

iii) ideal r/h is less than 65%; most people suggest 45% +- 5%

iv) an article in the Feb.  1990 Abbey Newsletter reports that "One estimate made on the basis of research is that the longevity of paper is increased 50% by storage at 30% rather than 45% RH."  High RH speeds up the damage caused by light, air pollutants, oxidation and hydrolysis.  Furthermore, the climate of the locality sets limits on the achievable range of RH.  "In dry, cold climates it may be impossible to push the RH above 20%..., and even if possible it may be inadvisable because of the resulting condensation on poorly insulated windows and walls."  There's a lack of consensus on this issue today.  For our region, 40% RH probably is a good upper figure.

v) measured using a sling psychrometer ($65) or with a recording hygrothermograph (drum in a box, turned by clock or battery mechanism, uses horse hair to detect changes in r/h and temperature) or with a thermohygrometer (little dial instrument, useful for exhibit cases; check it regularly against sling psychrometer for accuracy).  Michael Barford in NJ sells a Thermo Hygro for $59 which tells you minimum and maximum temperatures and relative humidities.

(c) mildew is a common type of mold, a simple plant in the fungi group

i) the spores of this mold are omnipresent in the air; we breathe and eat mold spores all the time

ii) mildew will grow on an substance from which it can obtain food--if conditions are warm (over 70 deg.  F) and damp (above 68% relative humidity) and there is poor air circulation and poor lighting

iii) not a common problem in our dry climate, except in basements, under water pipes, and in other damp areas

iv) it appears as small spots, grey, black or whitish in color, and produces a musty odor

v) susceptible materials include cotton, rayon, linen, silk, and wool fabrics, and also leather, wood, paper, and lumber.

vi) cellulose fibers are the most prone (paper, cotton, rayon, linen)

vii) protein fibers (in wool and silk) will mildew, but the problem is less severe with these fabrics; these fabrics are, in turn, more susceptible to insect damage

viii) if not prevented or treated, mildew can rot fabrics and can discolor leather and paper beyond repair

(3) preventive measures:

(a) keep the area and the objects clean; eliminate the spores' food supply

(b) eliminate dampness; use moisture barriers where building materials show signs of dampness

(c) if the relative humidity is above 68%, dry the air through the proper use of climate control eqpt and with dehumidifiers

(d) provide adequate ventilation, and use proper venting techniques

(4) treatment for a mildew outbreak:

(a) isolate the moldy items

(b) dry the affected items in a current of cool, dry air

i) a hand-held dryer is adequate for small problems

ii) avoid strong air currents that may dislodge fibers

(c) after drying, remove the growth with a brush or vacuum the items (use low suction), making sure that the removed growth is not allowed to recontaminate objects

(d) avoid chemicals; cheap and easy alternative to chemicals is to place a moldy item in the sun on a breezy (not rainy!) day for several hours and brush the mold off with a soft, natural brush

(e) practical steps: keep the air moving; arrange stacks of shelving parallel with the air flow and away from outside or basement walls to avoid excess moisture from leaks and/or condensation and mold and insects

b. fluctuations of temperature and relative humidity are the worst; cycling daily and seasonally puts a great internal strain on paper, which is hydroscopic--it expands and contracts in response to changes in moisture; this is esp. a problem when the paper is bound to a more rigid material, causing cracks and flakes

c.  when temp. rises, relative humidity falls, and vice versa, assuming that the moisture content of the air is static, because the air can only hold so much moisture at a given temperature

d.  "The isoperm model offers a relatively simple graphic means of describing the interrelationship of temperature and humidity in storage environments and predicting the increase or decrease in longevity that changes in either will produce." (Margaret Byrnes, National Library of Medicine, review in Oct.  1991 newsletter of The Commission on Preservation and Access.)  

e.  microenvironments are a recent concern of preservationists: a study conducted by the National Bureau of Standards for the National Archives concluded, among other things, that container can provide protection from the macroenvironment provided that they have not gaps in them; the prototypical container, the Hollinger records storage box, has a hole in each end which results in "diffusion of pollutants through the gaps at a rate that for practical purposes, t he container might as well be open." (reported in Oct.  1991 newsletter of The Commission on Preservation and Access.)

(a) enclosures slow down the shifts in temp. & humidity

(b) conditions inside an exhibit case may be like a greenhouse, subjecting the contents to 30-40 degree temperature changes over a 24 hour period

(c) avoid this

(1)  light is a type of energy, measured in wavelengths (nanome­ters)

(a) all light damages organic objects; light radiation causes photochemi­cal reactions

(b) visible light (400-700 nanometer wave length) causes the most fading, and causes chemical change

(c) the invisible ultraviolet rays (on the shorter end of the wavelength spectrum, 300-400 nanometers) also cause chemical change and can darken or fade paper, AND cause structural damage, making items brittle; u-v radiation comes from the sun (more at higher altitudes) and from unshielded fluorescent lights

(d) interestingly, ultraviolet light can be used to prevent microbial growth inside humidifiers (reported in the July 1989 Abbey Newsletter)

(e) the objects most affected by light include paper, textiles, wood, paintings, leather, feathers, and other organic materials.  Metals, stone and ceramics are not noticeably affected

(f) the rate of damage to an object is directly proportional to the amount of light it is exposed to

i) therefore, cutting the length of time a light is on an object in half cuts the damage in half

ii) similarly, replacing a 100 watt bulb with a 50 watt bulb also cuts the damage rate in half (Source: Fonda Ghiardi Thomsen, "Light Damage," National Park Service Conserve O Gram, July 1975)

(g) corrective/preventive measures center on eliminating as much of the damaging light as we can without eliminating too much of the light by which we see

i) keep storage areas dark

ii) reduce the time of illumination as much as possible

a) turn lights off after visiting hours

b) close shades and shutters on windows when sun is shining in

iii) eliminate ultraviolet radiation

a) daylight is the strongest emitter, followed by fluorescent radiation

b) apply UV filters to windows & fluorescent bulbs, and use UF-3 plexiglass on exhibit cases and in frames

c) choose ultraviolet-blocking tubes to start with: GE's deluxe warm white fluorescent tube #F40 WWX cuts out the UV to start with (per Randy Silverman)

iv) determine the amount of light your sensitive objects are being exposed to, and reduce it to recommended levels by using lower wattage bulbs and/or reducing the number of light bulbs

a) recommended foot candle levels:

   15 FC: oil and tempera paintings, undyed leather, horm, oriental lacquer

   5 FC: textiles, costumes, watercolors, tapestries, wallpapers, prints and drawings, dyed leather, fur, porcupine quill, feathers

   125 FC is the level of daylight coming through windows

 

b) control light's effects by eliminating harmful ultraviolet rays by keeping out bright sun, using filters, and/or changing the type of light; also, by connecting the lighting system to a motion detector so that an area need only be lit while people are in it (a system noted in the July 1989 Abbey Newsletter uses a computer; it's called Static Lighting, and is available from Richard Spencer in Crete, NE)

c) visible light also is damaging, because of its intensity and duration (also determined by the type of light)

d) photochemical damage manifests itself in bleaching (common with rag paper), and yellowing, fading and brittleness (all common with ligneous paper)

e) effects of exposure to light are cumulative and irreversible, and the energy already absorbed by an object makes it that much more susceptible to further damage

(2)  airborne pollutants such as dirt and dust (which can cause acidic attacks, "foxing" = little brown specks on paper as it reacts with metallic elements in the paper), sulfur dioxide (car emissions, catalyzed in moisture to form sulfuric acid); insects and rodents like dark and dirty environments

f.  biological agents: mold, vermin, insects

(1) be a good housekeeper; keep the storage area free of dust, mold, and vermin, and provide an environment inhospitable to them; prohibit eating and drinking in or near the storage area

(2) remove infested materials from storage

g.  storage, security, and use/handling:

(1)  storage (do class exercise based on Ritzenthaler's NEDCC manual for storage)

(a) use only pH-neutral materials for storage; boxes should be airtight (see above discussion of microenvironments)

(b) housing of manuscripts - two types:

i) document boxes, storing folders vertically, sometimes using polyester sleeves

a) shouldn't be underfilled or overloaded

b) don't overpack material on shelves or in boxes

c) avoid placing acidic materials such as newspaper clippings next to other items

d) books in boxes should rest on their tails, not on their fore-edges or spines

ii) through the late 1970s, lamination was a popular means of preserving much-used documents: putting a laminate of mylar/tissue/document/tissue/mylar into a heat press that melts the plastic into the document; problem is, document remains acidic, and the process isn't reversible; solution: put item into alkaline solution bath, then encapsulate it in mylar sealed on the edges.

iii) (source: Colorado Preservation Alert newsletter, Dec.  1991, article on encapsulation by Sharon Partridge): "Encapsulation does for a single page what phase boxes do for books and pamphlets.  In addition to protecting the item from the environment, encapsulation makes it possible to handle extremely fragile paper.  Placing the document between sheets of inert (chemically inactive, doesn't interact with the paper) plastic sets up a static field which makes use possible.  While this does not decrease the brittleness of the paper, the enclosure does prevent further breakage.  ...  It is better to do any deacidification, mending and cleaning (Scum-X works well for cleaning...) before encapsula­tion..."   {demonstrate encapsulation of an important or fragile document} (may fold Mylar in half and crease, allowing for .5" borders on all 4 sides; double-sided tape on one side touching the fold, leaving 1/8th inch space between paper and tape to avoid migration of the adhesive and likewise between tape and edge of Mylar so external dust and dirt won't be attracted to the adhesive, and when taping the last two sides leave a 1/8" gap where pieces of tape meet at the corners to allow the emission of gasses from the paper as it deteriorates and breathes; use a paper weight to hold the free corner up while applying the tape to reduce frustration; roll from the finished corner to remove excess air and air bubbles) - pre-made polyester envelopes are available.

iv) alternative method: sew with a zigzag stitch of nylon thread; this allows for the necessary ventilation

v) do test for PVC in bad plastic, burns green when poked with hot copper wire (hold it with pliers!)

vi) in an article in the Sept.  1989 Abbey Newsletter entitled "Not All Mylar is Archival," Tuck Taylor reports that DuPont now makes over 100 varieties of film from polyester, all of which are called Mylar.  This includes a form called M-30, which is coated on both sides with polyvinylidene chloride, which over time can break down and give off something like hydrochloric acid.  The appropriate form of Mylar for archival work is film that is uncoated, biaxially oriented, with not chemicals or particulates added to the base sheet; Type D is the most recommended form of Mylar for our use.  ICI, 3M, and American Hoescht also sell the equivalent of Type D Mylar.  The point is, one must do one's research before ordering archival supplies!

vii) of the three possible plastics (polyethylene, polypropylene, and Mylar type D), Mylar is the toughest, the most scratch resistant, clearer, and is absolutely inert; choose 5 mil

viii) (Partridge, continued) comparison of encapsulation and lamination is indicative of several archival principles: "Lamination, in contrast to encapsulation, is a heat-activated procedure which involves the use of chemical adhesives which penetrate the paper.  The temperature required for adhesion is 250°F+ which accelerates the aging of paper and can actually discolor some papers immediately.  Also, the plastic used, poly-vinyl chloride, is a culprit in accelerating paper deteriora­tion."   Lamination, unlike encapsulation, is irreversible, and is not archival process.

ix) {what archival principles does the comparison of these two methods demonstrate?}

(2) bound volumes, either

(a) hinged by cloth on paper along one edge, edge mounted, inset into matting windows (glued on the edges), or solid mounted (adhesive all over the back of the document), or

(b) directly bound into a volume and sewn in, or

(c) laminated and then bound, with the extending laminating strip serving as the hinge; this binding is expensive (esp. to support the weight, to lie flat, open fully, & be acid free), time consuming, irreversible, and the hinge paper and backing material can be incompatible with the document

(d) commercial binding is an important preservation technique

i) not oversewn, because oversewn volumes cannot be opened to lie flat

ii) preferable method is sewn through the fold

iii) books wider than 2" should have a rounded back (spine), not a flat back

iv) the Library Binding Institute has a Standard for Library Binding, and NIC has a Collections Care bibliography ($20 incl.  shipping)


(3)  security

(a) concern about potential damage from people and from the elements (esp. fire)

(b) prior question is, what do you consider the desired lifetime of your materials

(c) whether perceived or not, aging is producing changes in all items, so faster than others

(d) protect the storage area from fire, flood, theft, and intrusion

(e) in 1975, fire destroyed 20 million files on the 6th floor of the federal records center in St.  Louis, Missouri; this persuaded archivists to use smoke detectors and sprinklers, and not to shelve Hollinger boxes with the opening lid facing front--files fell out when front burned; loose sheets of paper are more flammable than tightly bound and closely shelved library books

- what about putting the repository's stamp on the documents?  many drawbacks: (1) where to stamp it without defacing the document? and (2) how will repository know it's missing (without an item inventory) or whether it's just misfiled? -- so, don't bother, have other security measures for the handling of documents sought by researchers - charge-out slips, sight-lines in research area, storage lockers outside of research room

(4)  use/handling

(a) staff use/treatment: issues of rough/improper/frequent handling; photocopying; improper storage; misguided repair or restoration

i) conservation steps must be reversible; with training, in-house conservation can include removing all staples, brads, paper clips, and rubber bands and replacing them with file folders (if further grouping of items is necessary, use stainless steel paper clips over archival paper, but not plastiklips which can bend and tear paper); never use scotch tape or glue; use non-abrasive erasers; mend small tears with archival mending tape; encapsulate fragile items in polyester film (Mylar)

ii) avoid Postit notes, which leave a gum residue on the surface and in the fibers of paper and stain the paper

iii) dry clean papers using Skum X (ground vinyl with calcium carbonate in it), which is slightly abrasive but doesn't remove pencil marks; it's like parmesan cheese--sprinkle it onto the paper, rub it in circles with your fingers, and reuse it until it's dark grey (mfd.  by Dietzen); use Mylar to block off sections you want to protect from the cleaning agent and to support your hands while cleaning a large fragile item; this poweder is easier on paper than an eraser, which is esp. apt to damage the surface of shiny glazed papers

iv) label in pencil; avoid labels, which are not permanent; no adhesive is non-damaging, because glue ceases to adhere at the point when it stops reacting with the paper

v) encapsulate super-valuable items

vi) store maps flattened in drawers no more than 2.5" high, using folders all of the same size (2" narrower than the cabinet interior), with the fold facing out to keep people from rummaging while folder is still in drawer; less than 30 maps per folder; fewer than 10 if they're rare items; fold a very large map once (per Cuniff); LC cuts maps into sections to house huge ones; place large 3-D globes and map models on permanent display

vii) for paper repair, use methyl cellulose glue rather than wheat paste (which doesn't keep, and which attracts insects and vermin); this glue is what makes Twinkies last forever; buy it in powder form and mix it with water; choose Japanese mending paper of a weight comparable to that of the paper being mended; dampen the paper and tear it so it has furry hairy edges, and match the grain of the mending piece to that of the paper before attaching it with methyl cellulose

viii) flatten a fold by applying a damp brush to it; this will relax the fibers so it'll fold flat without breaking; only do this if the ink is stable

(b) principles of repair:

i) do no harm

ii) use a reversible process

iii) keep it simple

(5)  exhibition

(6)  disasters

(a) discuss BMS disaster plan and case study

(b) water damage: if 100 books or more have suffered water damage, freeze them first; if fewer, dry them to 20% paper moisture

- all 5 above factors are interrelated and are very complex


E.  So, what would be the perfect environment?

1.  totally dark and away from people, with no change of temperature or relative humidity and no pollutants

2.  (Abbey Newsletter, ) Arctic Circle archives


F.  SUMMARY OF ADMINISTRATIVE CONCEPTS REGARDING COLLECTION PRESERVATION:

1.  approach preservation as a management strategy/ the administrative approach to collection preservation

       a.  don't deal with problems in items as they appear; instead, have a systemic program

b       .  everything deteriorates; we are only trying to slow the rate for specified categories, because we realize that our civilization's record of knowledge is endangered

2.  a conservation program must succeed from an administrative point of view, under a preservation administrator who plans staffing and finances and relates conservation to other tasks of the institution, and trains the technicians in conservation


G.  Seven basic components of an archival conservation program:

1.  environmental controls - 50% r/h, 70 degree temperature, low sunlight, timer switches for lights in stacks, nonfluctuating temp. & humidity (use hygrothermograph to monitor)

2.  stack maintenance - routine dusting (use Dust Bunny), emptying trash, keeping shelving neat and shelf dividers in proper places

3.  disaster preparedness - for before, during, and after a disaster; making the archives disaster-proof; practicing the plan and distributing it to the staff

4.  processing procedures for the collections, for housing them properly, for routine materials for treating and reformatting; recognize that preservation is a strategy for increasing circulation and for stretching collection resources

5.  staff/user education - rules regarding use of pencils instead of pens, no eating and drinking in archives; no marking documents; using a limited number of folders, books or boxes at a time; registration procedures; maintaining the order of the materials

6.  physical treatment of collections - very expensive; only for the most valuable documents

       a.  conduct a general preservation planning survey

        (1) purpose: identify specific goals and priorities for the long-term protection of the institution's collections

               (a) this includes eliminating hazards such as water, fire, and theft

               (b) also includes developing strategies to preserve materials in the best condition possible for the longest achievable time

               (c) improved housekeeping and improved climate control (specifically the stabilization of daily and seasonal fluctuations in temperature and relative humidity) usually are the two most important factors in protecting the collections from further deterioration

                     i) it's not the Kleenex that scratches your glasses, it's the dust, acting like sandpaper; keep it clean!

                     ii) inspect your shelves regularly for worm poop, which looks like sawdust; in this region we face terminal silverfish (active at night), cockroaches, bookworms (larvae of beetles/termites etc.), which lay eggs at the base of books, hatch, and begin eating the books

                     iii) damp sponge is preferable to vacuuming dusty shelves; better yet, use a Dustbunny which employs static electricity to trap the dust into the cloth

                     iv) even badly deteriorated paper can be protected from further damage if it is stored in appropriate enclosures in a well-controlled environment

                     v) in many instances, systematic introduction of alkaline-buffered boxes or other archival enclosures will be a high priority

        (2) survey the components

               (a) examine building conditions from roof to basement, outside and inside, room by room

               (b) examine collections, storage, and handling procedures

               (c) identify potential hazards to the collection

b. develop a preservation plan

        (1) prioritize areas of the collection for preservation action

               (a) ­e.g., accessibility as is, availability in current format, relation to the whole collection, past and expected use, how long it will last as is

               (b) this involves a dialogue between the archivist and the conservator

        (2) identify actions required to insure the long-term preservation of collections

        (3) prioritize the needs of the collections and identify steps necessary to achieve the required preservation actions

        (4) set short-, medium-, and long-term goals

               (a) some actions can be implemented immediately and at very little cost

               (b) other actions may require diplomacy, education, and fund raising

               (c) each improvement will contribute in part to the survival of the collections

c. one method of mass physical treatment of documents is deacidification

        (1) much is being researched and written about this topic; previously, books had to be taken apart and their pages soaked in a deacidifying solution one page at a time

        (2) most current pilot methods of mass deacidification involve vacuum drying and heating of bound volumes, eliminating the acid in them by soaking the books in a basic alcohol solution under pressure which penetrates the pages, then drying the volumes without toughening the cellulose fibers.

        (3) traditional drying methods required heating the wet paper quite fiercely, a thermal process which could alter the mechanical properties of the paper.  A 1989 article entitled "Microwaves that save manuscripts" describes the use (in France) of the electrical energy of microwaves to selectively remove molecules of "free" water that have not seeped into the paper; this residual moisture ought to be left in the paper; this process preserves the paper's chemical and physical properties and takes place at a low temperature

7. reproduction of brittle items, deciding whether to keep with collection, or microfilm?

       a.  National Archives runs 10 microfilming cameras 5 days a week (as of 1985), has done 5% of its holdings since 1942 - some 200,000 roles of film -- never expects to catch up

       b.  most archival microfilm is 35 mm, sprocketless for a larger image; 100' of film on a roll can hold about 1,000 pages of documents

       c.  photocopying onto pH neutral paper with a color laser printer photocopier yields a permanent copy (per Chloe)

8.  security is an aspect of preservation: preserving documents for the use of future generations--this includes taking such steps as producing finding aids and microform copies


H.  Special preservation problems of certain types of media

1.  photographs and related photoproducts are unstable media (source: Margaret A.  Cribbs, "Photographic Conservation--An Update," ARMA Quarterly, July 1988, p. 17-19)

       a.  they begin to lose their quality the moment they are created

        (1) chemicals in today's prevalent mass-produced photos printed on resin-based paper immediately begin to break down the image emulsions

        (2) other agents that have an adverse on photoproducts:

               (a) heat, humidity, fungus

               (b) static electricity

               (c) oils from human hands

       b.  photo preservation is possible

        (1) under bad conditions, damage can be noticeable in as few as 3 years, but with proper care photoproducts can be preserved for up to 100 years

        (2) decisions about preservation media should be made with 3 elements in mind (source: ProQuest abstract of Margaret Cribbs' article "Photographic Conservation--An Update" in ARMA Records Mgmt.  Qrtrly, July 1988, p. 17-19):

               (a) projected use

               (b) projected budget

               (c) environment

       c. standards for archival photos

        (1) "Silver halide photographic film, processed according to ANSI and federal standards, is a certified archival medium whose long-term storage properties are known and acceptable." (Source: John C.  Mallinson, "On the Preservation of Human- and Machine-Readable Records," Information Technology and Libraries, Mar.  1988, p. 21) (ANSI is the American National Standards Institute

        (2) archival photographic images ought to be on a polyester base, such as is common for "archival" microfilm, some motion picture film today, and most of today's 4x5, 5x7 etc.  sheet films; roll film now being manufactured for 35mm and 70mm photograph cameras is made of a less stable cellulose acetate base.  Cellulose based films are not good candidates as preservation copies, because they will deteriorate (by shrinking) with high temperatures and humidity and atmospheric pollutants.  "The vinegar smell coming from older cellulose acetate collections is evidence of their deterioration.  Future archivists are going to be kept very busy trying to preserve the images on today's roll films." (source: e-mail from Peter Roberts, Archivist/ Asst.  Prof., Georgia State University, 19-Jun-1992)

        (3)  archival enclosures for photos (cf.  my Occasional Paper)

               (a) Mylar or polypropylene are appropriate for materials that will be consulted frequently, if humidity is controlled and is kept below 65%

                     i) advantages of this material: it allows for visual access without physical handling

                     ii) disadvantages: it can trap in moisture; also, it can't be written on, it creates static electricity which attracts dust, and it affords no protection from light

               (b) less expensive unbuffered pure alpha cellulose paper envelopes can be used for archival storage where little handling is expected; the paper is porous, allowing transmission of moisture, it's less expensive than Mylar, and can be written on (use pencil)

               (c) avoid glassine, commonly used due to its cheapness, lightweightness, and translucency; avoid it because it will stick to the emulsion surface if too wet and because it can be abrasive

               (d) store the materials in metal cabinets or in acid-free boxes on metal shelving; use metal with a baked-on finish

               (e) avoid binders

                     i) boxes provide a second layer of insulation against many of the agents that cause degradation of photos: light, atmospheric pollutants and changes, etc.

                     ii) studies indicate that users tend to be more careful in handling boxed materials than bound ones

                     iii) the components of conventional 3-ring binders are not archival: many contain polyvinyl chloride (PVC)

                     iv) turning pages can be troublesome when the rings are askew

                     v) photos stored in binders tend to bow under their weight or by being turned

        (4)  maintain a constant cool temperature and stable low humidity

               (a) the colder the environment the better, esp. for color images, which are inherently more fragile than b/w

               (b) Debbie Hess Norris recommends 35 deg.  F max.  for color images, with RH under 50%

               (c) "consistency is most critical, since fluctuations in temperature or humidity can do more harm to photographic materials than can a warmer more constant temperature" (p. 18)

        (5) authorities on photo preservation to consult as needed:

               (a) Debbie Hess Norris (Winterthur Museum, Wilmington, DE)

               (b) James Reilly (Image Permanence Institute, George Eastman House, Rochester, NY)

               (c) Siegfried Rempel (National Archives of Canada; author of The Care of Photographs, by Nick Lyons Books, NY, 1987)

2.  Video preservation: the National Library of Medicine suggests the following (email from Sarah Richards, 17-Apr-1992): "We make a `bump up' 1-inch analog or D2 copy (sometimes both) of a VHS videocassette which we wish to preserve.  Additionally, we make another 1/2 inch VHS copy for in-house service and for interlibrary loans.  Our plan is to keep both the original VHS and the preservation copy (1-inch or D@) in a vault at 60 degrees F.  and 25% RH.  When the formats we've transferred to start to become obsolete or change, we will have to make new copies in the most recent format.  The better equipment for video transfer will be found in commercial transfer houses, not those found in stores for non-professionals.  We send all our transfer work out to commercial laboratories.  For further information of preservation of film or video, you can call the Association of Moving Image Archivists' secretariat at (213) 856-7600."  

3.  Preservation of machine-readable electronic records (Source: John C.  Mallinson, "On the Preservation of Human- and Machine-Readable Records," Information Technology and Libraries, Mar.  1988, p. 19-23)

       a.  there's "an unfounded [prevalent] belief that some unidentified future technology will emerge to resolve most of the present and future machine-readable record problems." (p. 19)

        (1) the data recorded on MRR's, such as magnetic computer, audio and video tape, magnetic and optical disks, and phonograph records, can only be recovered by converting it to a human-readable form, such as paper text, photograph, sound, or video terminal display.  (p. 19)

        (2) "the machines themselves--computers, satellites, and TV receivers, for example--are rarely expected to have a useful life in excess of ten years."  (p. 20)

        (3) to store more information and to decrease access time, MMRs "are operated at ever-increasing information storage densities, a trend that is surely inimical to long-term archival preservation" (p. 20)

        (4) obsolescence is rapid: 10 different incompatible videotape formats since 1956, at least 3 of which are obsolete, and 8 different computer tape formats since 1952, half of which are obsolete.  Each format typically requires a different machine with its own unique set of demodulators, decoders, reformatters, etc.  (p. 20)

        (5) "the proliferation of incompatible systems is the root cause of the archivist's dilemma with machine-readable records." (p. 20)

        (6) "Since the information and communication industries are most definitely not driven by long-term archival considerations, it seems to be futile to expect technology to resolve this problem.  Technology continues to cause the `machine-readable' problem and will not solve it." (p. 20)

       b.  archival properties of magnetic and optical recording media

        (1) 3 components of magnetic tape

               (a) base film (an exceptionally stable plastic: Mylar, Estar, Celanar, etc.)

               (b) the particular binder system

                     i) usually  of polyesterurethane

                     ii) s­ubject to hydrolysis

                     iii) reaches a satisfactory equilibrium sate at 65-75 deg.  F, 40 +- 5% RH

               (c) the magnetic particles

                     i) usu.  iron oxide

                     ii) iron oxide is stable, less vulnerable than other materials used such as chromium dioxide and elemental iron

        (2) expected life span

               (a) a controversial topic with no absolute answers

               (b) "generally...it is believed that magnetic tapes, properly stored, will outlast the hardware (computer drives, videotape recorders, etc.)" (p. 21)

               (c) current estimates are of 10 to 30 year lifetimes for metallic disks, depending on disk quality, storage, and handling (i.e.  only hold a CD by its edges, and store it in its case)

        (3) despite initial glowing claims about their protective coating, etc., CD-ROM disks are not indestructible; in fact, they can be damaged fairly easily.

               (a) aluminum, the brains of the CD--the metal used by most CDs for storing data, oxidizes easily (Source: ProQuest abstract and article by Alan King, "The Care and Feeding of Your CD-ROM Disk," Database, Dec.  1991, p. 105-107)

                     i) "CD-ROM disks work by storing data on [a] highly-reflective and incredibly thin coating of aluminum, that covers a poly-carbonate plastic surface.  Data are encrypted onto the aluminum as a series of subtle alterations to the reflective surface--resulting in the ubiquitous `on or off' binary notation that is the foundation of computer technology." After the data are applied to the aluminum, the sheet is hermetically sealed with another layer of plastic, and the label is printed directly onto this final surface.  "The CD-ROM drive then reads this information and relays it to your computer system, which translates the `ons and offs' into something" we can understand.  (p. 106)

               (b) air, water, or other matter can be trapped between the aluminum coating and the plastic coating during the pressing process, setting the disk up for oxidation

               (c) inks used in the labels can eat away at the plastic surface, exposing the aluminum layer

               (d) sloppy quality control during the pressing process can cause minute cracks in the plastic layers

        (4) gold is being considered as an alternative, but it costs substantially more

               (a) thousands of damaged disks are returned to the manufacturer for replacement each year, usu.  due to scratches or nicks on the surface of the disk; a single scratch or smudge can render thousands of bytes of information useless

       c. archival properties of software and documentation

        (1) MRRs using computer or digital (not analog) technologies require the proper operating system at the time of data recovery

               (a) operating systems are changing even more rapidly than the hardware

               (b) Western Electric's UNIX operating system has been offered in more than 30 versions in one decade (p. 21-22)

        (2) also, appropriate documentation must be on hand to provide the necessary info on the digital codes used, the organization or format of the record, and several other minor but critical details

d. archival properties of hardware

        (1) expect a life span of no more than 10-20 years

        (2) who will maintain a 1980s vintage machine in the year 2200?

        (3) thus, an archival institution accepting MRRs is committing itself to eternal file conversion--copying records from the old, obsolete format into the new, current format approximately every 10-20 years, and this is an expensive preservation strategy (p. 22)

e. solutions?

        (1) Subcommittee C of the Committee on Preservation of the National Archives recommended (in late 1980s) "that NARA store and preserve most of its future accessions in a human-readable microfilm mass memory."

        (2) "The subcommittee members, all senior technologists in their respective high-technology organizations, have unanimously come to believe that these recommenda­tions are the only solution that is logically defensible today.  While risking being characterized as `technological Philistines,' they, nevertheless, welcome debate from any quarter." (p. 22)

 
I.  Recent efforts and trends in preservation:

1.  collection level treatment, including preventive measures

       a.  archival emphasis on the group is important in conservation; value of archival documents is associative, and archival collections tend to be large (LC has 40 to 50 million items)

       b.  forced by the incomprehensible scope of the problem, including growth of collection volume, inherent vice, and fiscal constraints

2.  cooperative approaches

       a.  regional centers (Rocky Mountain Conservation Center, Northeast Document Conservation Center)

       b.  national and international efforts

3.  limited funding for preservation
 

J.  Practical application, in summary:

1.  An archival rule of thumb is to DO NO HARM.  This includes leaving materials in their original order (if it's a sensible order) as presented in Archival Key #3 and Archival Key #4) so that we maintain any context that has existed between the various documents in a collection.

2.  Another aspect of this is that archivists respect old age.

3.  Any processes we use should be reversible.  (There are inevitable exceptions.)

4.  Light is a form of energy.  The effects of exposure to light are cumulative and irreversible.  Therefore, we must limit the intensity and duration of exposure to light.


K.  Assignments: 
1.  Do Trudy Peterson's exercise #9 (p. 79) regarding preventing theft in archives.

2.  The Northeast Document Conservation Center (NEDCC) has a Preservation Services department that "provides free preservation advice to institutions and individuals worldwide. The Center provides Preservation Leaflets with information on a wide variety of preservation topics and links to additional resources."  Look at some of them that interest you, free online.

3.  Read some of the preservation topics at CoOL (Conservation Online).