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CHAPTER 2 Paper, Parchment, and Vellum

Most manuscripts, legal documents, ullic records, diplomas, drawings, and many other two-dimensional artifacts are created on paper, parchment, or vellum. Paper is produced from the pulp of wood; parchment and vellum are made from the un-tanned skin of animals. In the Middle Ages, the term vellum was used to describe fine parchment. Vellum was sometimes dyed a rich purple for very important documents.

Preservation Concerns

The preservation concerns for most two-dimensional works can be divided into:

1. Issues with the support, such as the paper or parchment.

2. Problems with whatever medium was applied to the support, such as ink, charcoal, or pencil. Paper supports are very prone to acid deterioration. Paper is made from cellulose extracted from wood pulp by strong chemicals. The paper produced contains acids left over from the pulping process. Additional acids build up in paper as the lignin in the pulp deteriorates with age, and with exposure to the sulphuric acid that is produced when the moisture in the air contacts sulphur dioxide from coal and petroleum combustion. Art and documents discolour and become brittle as these acids cause deterioration of the molecular structure.

Parchment and other hides are naturally very strong and can withstand a great deal of manipulation due to their composition. During the preparation of hides, alkaline substances are applied making the sheets resistant to acid deterioration. The greatest preservation issues relate to their extreme sensitivity to moisture. Hides often illustrate varying degrees of buckling and deformations due to changes in the relative humidity. This buckling can be so severe that it interferes with the aesthetics of the piece.

Paper, too, can buckle or become deformed due to changes in relative humidity, but the more troublesome risk of exposing paper to high humidity is foxing. Foxing refers to small brown spots that form on paper that can be visually disturbing and result in small holes. It is thought that foxing is a mould growth as a result of impurities in the structure of the paper or the sizing material that was applied to the paper during production.

An exposure to water or 68–70 percent RH will allow mould to attack the sizing applied to the paper, the medium, or the structure of the paper (cellulose), parchment, or vellum. Mould is a health hazard and it disfigures and visually alters artifacts.

Other problems common to paper and parchment supports include discolouration, yellowing, darkening from light exposure, fading, or colour change due to light exposure, darkening due to exposure to acidic materials, matt burn, liquid staining, oil staining (frequently from fingerprints), media-induced staining, adhesive staining, adhesive residue, creases, folds, tears, holes, surface abrasion and fibre loss, pinholes, flyspecks (which appear as dark irregular dots), insect damage, attachment to inadequate or damaging support materials, applied adhesive, or damage as a result of previous inappropriate repairs.

Table 1: Environmental Recommendations for Paper-Based Artifacts

The media used to produce documents and works of art on paper can be just as prone to deterioration as the paper supporting them. Although graphite and pencil are relatively stable, pastels, charcoal, and chalk are all powdery and smudge easily. There are commercially available fixatives, but they should probably be avoided as they can change the colour of the pigments and trap dirt on the surface; some have been linked to deterioration of the paper supports. It is common for twentieth-century blue and black inks of fountain, ballpoint, and felt-tipped pens to fade to a brown colour because the inks were made from dyes rather than pigments. Some of these inks are so unstable they even fade when in dark storage. Older inks also have problems, especially early twentieth-century iron-gall ink. The gallic acid reacts with the iron resulting in corrosion that destroys the paper on which the ink was written. This appears like burns and holes in the paper.

Tempera and other paints applied to a sheet of paper or parchment can begin to flake or powder, resulting in losses from the image layer on the support. When the support, whether paper or parchment, is not handled properly when moved, it flexes and bends causing the more rigid applied media to flake off. Movement in the form of small expansions and contractions also occur when there are changes in the relative humidity. This too results in losses of the applied media.

Specific rules for handling various artifacts are given in Appendix 4: General Rules for Handling and Moving Artifacts and Works of Art, but here are some general guidelines to remember:

• Try not to directly touch the artifacts. The oils occurring naturally on your skin can damage and stain your treasures.

• Handle items with mount and matt boards by the supporting board.

• Handling un-mounted sheets by lifting them by the upper corners so that they hang freely without bending.

• Wear gloves when working with artifacts. White cotton gloves are recommended.

• Always place artifacts on a clean and level surface.

Preventative Conservation

The first step in preservation is to always thoroughly examine your artifact for damage and potential problems and check the overall structural stability of the work. One of the most common and helpful things that can be done at home is a very light, dry surface cleaning to reduce the amount of dust, fibres, and other foreign material that may have collected on the surface. Never attempt to clean brittle papers or powdery media, such as pastels, chalk, charcoal, or painted surfaces.

Surface dirt should be removed not only to improve the aesthetic appearance of the piece but also to eliminate a hazard. Dirt is abrasive, it can be acidic, and it holds moisture, which promotes the growth of mould spores. If your work can tolerate a light cleaning, you will need a very soft natural bristled brush, an air bulb (either the type used for a baby’s nose or those sold at photographic supply stores), and a drafting brush.

Wearing white cotton gloves, you should begin by gently blowing away any loose surface dirt with the air bulb. Follow this by brushing lightly with the soft natural bristled brush. Begin brushing from the centre of the object and work toward the edges. Use very light pressure; the paper should not move with your brush strokes. As dirt and dust accumulate around the edge of your artifact and on your work surface, remove it using the drafting brush. Once the surface dirt has been reduced, the artifact can be prepared for storage or display.

Storage and Display

Where items will be stored is as important as the method and materials for storage. Roofs leak, basements flood, and the temperature in attics fluctuates greatly day to night and through the seasons. Careful consideration should be given to the type of artifact to be stored and the conditions of storage. In bad conditions, deterioration can happen rapidly and with heart-breaking consequences.

Once you have determined a location for storage, chose the storage method and materials. Print files or drawers available from office, art, and drafting suppliers are very space efficient. Metal files with a baked-on finish are preferable to wood because wood is acidic and acid contamination can be transferred to your stored artifacts, resulting in damage.

Solander boxes or storage boxes made from acid-free corrugated board, acid-free and lignin-free box boards (TrueCore), or corrugated copolymer (Coroplast) can be arranged within the metal file drawers to help organize your holdings by size, subject, or medium. Ideally, artifacts should be matted prior to storage, but this is very costly.

When stacking matted, mounted, or loose artifacts, place separation sheets between each work. There are many materials that can be used to separate the artifacts: glassine, interleafing tissue, Permalife paper, Melinex (clear polyester film), or PermaDur to name a few. Each has advantages and disadvantages and you should research which is best for your collection. Table 2: Papers and Characteristics offers a limited comparison of some of the archival papers available. Folders made of acid-free stock are another alternative for sorting your collection and separating works within file drawers or boxes.

Damaged items can be protected by placing the items in a folder or an envelope or by encapsulating the artifact between two sheets of clear polyester film (Melinex — see Appendix 5: Encapsulation Process). Do not confuse encapsulation in polyester film with lamination. Lamination is an irreversible process involving heat. No document or artifact should ever be laminated. Never encapsulate artifacts with powdery surfaces, such as pastels, charcoal, or chalk, as the static of the polyester will destroy the image. Static from polyester will also cause additional damage to artifacts with flaking paint.

Table 2: Papers and Characteristics

* Prices quoted are for the smallest size and quantity available for purchase, rolls are more economical.

In preparation for framing or storage, paper and parchment artifacts are often matted or mounted. In many instances, this is done improperly and causes additional damage rather than protecting the work of art. The boards used for matting and mounting are not always up to conservation standards. Just because a framer offers a board, it should not be assumed that it is adequate for your artifact.

Poor quality boards are acidic and can cause matt burn — a darkening where the board touches your artifact. Matt burn weakens the paper and causes it to become brittle. Always specify that you would like an acid-free, 100 percent rag, conservation-quality board. Ask to see the board and confirm the maker and grade.

There are many framer’s tapes, adhesives, and methods of adhering your artifact to the mounting board. Never use pressure-sensitive adhesive tapes, heat-activated adhesives, or “dry mounts” to attach your artifact to the mount board. These methods can discolour or stain your object, cause deformations, result in breakages as your object expands and contracts with environmental fluctuations, cause your object to become brittle, or weaken your artifact. These adhesives are difficult, if not impossible, to remove. Your artifact should never have an adhesive applied completely over the reverse or on all perimeter edges; it should be hinged at the top edge only (see Appendix 10: Matting and Framing Paper Artifacts).

Matts and mounts applied by an artist are historically and aesthetically important. They should be maintained and, if possible, incorporated into the new mounting package. If in doubt, find someone to consult prior to taking action.

When to Call a Conservator

Maintaining a collection means that with time you probably will encounter damage and problems that require the attention of a conservator. It is important to know when you should call on a specialist.

Buckling and Deformation from Plane

When parchment, vellum, and other hides begin to buckle due to high humidity or exposure to moisture, the fibres of the tissue that form the structure are losing their directionality due to a loss of tension. Some buckling is expected and, if it is minimal and does not interfere with the aesthetic appeal of the work, it may not need immediate professional treatment but may need some preventative care at home. If the deformations do affect the visual appearance of the work or are causing the paint or other decoration to flake, you should consult a conservator. The same is true for paper artifacts.

Water Damage: Tide Lines, Mildew, Mould

Tide lines occur as water and impurities are wicked through paper or other support and impurities are left behind as the water evaporates. Tide lines should be referred to a conservator since trying to remove them could result in additional movement of the impurities.

Parchment is extremely sensitive to water and moisture. Therefore any stain removal, cleaning, or repair of tears should be referred to a conservator.

Mildew refers to a specific kind of mould or fungus, usually related to agriculture, that has a powdery or downy appearance. But the term is generically used to refer to mould growth that has a flat profile.

Mould is always present in the air. Given the right environmental conditions, it will begin to grow on any suitable surface: glues; sizing applied to paper or clothes; paper; and invisible oily fingerprints. Mould colonies grow in many colours, from bright pastels to black, and are sometimes hard to detect. Often a musty odour first indicates the presence of mould or mildew. If the mould growth has not progressed too far into the structure, it can be brushed off, but this is not prudent as the spores can enter your lungs and colonize. Mould is a health hazard as well as a hazard to your artifact and should be referred to a conservator.

Tears, Breaks, and Losses

Tear, breaks, and losses should always be repaired by a conservator. Never try to fix these problems with tape or adhesive as this will often lead to additional damage and a more costly and difficult treatment later. Damaged items should be treated by a conservator but can be encapsulated or stored in an acid-free folder so that no pieces are lost until conservation treatment is possible.

Stamps

Adhesive backed stamps should be handled with great care. The humidity and oils on fingertips can easily disturb the surface of the adhesive. Always wear gloves and use wide-tipped tweezers to move stamps.

The adhesive on the back of many stamps is susceptible to high humidity that can cause the adhesive to stick to adjacent materials. Do not hinge or mount previously unused stamps with adhesives. This will lower the value of the stamp.

Many stamp collector supply houses offer photocopy protection pages, pages that prevent copying of the stamps, and black mounting pages. Tests have shown that many of these pages are acidic and will cause damage and discolouration of the stamps with long-term exposure.

Stamp storage should be uncoated polyester, acid-free buffered paper, glassine, or parchment paper. Polyester sleeves can be stored in a three ring binder, some of which “zip” open down the side for easy access and to allow viewing of both sides of the stamp. There are mounts for individual stamps that require no adhesive. Once mounted, stamps can be stored in an acid-free box.

Trading cards

There are different grades of trading cards. Common cards that are purchased in packs have a low monetary value. Popular cards that are collected because of the card image or information also are of little monetary value. Premium cards are ones that have a monetary value of over five dollars. The most valuable are sets that have been left in their original factory packaging.

Usually common cards are stored in boxes. Acid-free boxes are recommended since you never know when a common card may become valuable. Sets are also usually stored in boxes. When you buy a set, it is usually sealed in a printed Mylar (Melinex) envelope or sealed in plastic. Sets should be handled infrequently and with care. You should wear gloves because damage to the plastic or the image printed on the Mylar lowers the value of the set.

Popular and premium cards are usually stored in sleeves. There are sleeve pages that hold two to nine cards that fit into binders. There are also sleeves for single cards that would then be stored in an acid-free box. There is a wide range of different materials and quality sleeves available. It is important to insure that you are storing your trading cards in polyester sleeves. Sleeves should be acid-free, and plastic sleeves should not contain PVC. Again, always wear cotton gloves when handling premium cards.