Works of Art on Paper

Introduction

Works of art on paper include a range of items: watercolour paintings, prints, posters, and drawings, including your child's artwork. There are a variety of media used: watercolour, charcoal, pastels, coloured inks, graphite or pencil, and even crayons and markers.

Whether these works of art adorn your walls or are stored away, it is important to take basic precautions to preserve them. Doing so will not only prolong your enjoyment of them, but will also help ensure their longevity.

Damage and how to prevent it

Paper is made from fibrous material, such as rags, straw, bark, or wood. All these fibre types contain cellulose, the basic component of paper. In general, plant types that yield the highest cellulose content and the fewest impurities make the best quality paper. All paper, however, is vulnerable to damage from a variety of sources.

Handling is probably the most common cause of damage. Paper is easily torn, creased, or stained. The best handling method is to handle paper as little as possible. To prevent damage from oils and salts on hands, it is advisable to wear white cotton gloves. When lifting your artwork, slide a stiff paper or matboard below it before moving it. Avoid eating, drinking, or smoking near the paper and keep pens and markers away.

Exposure to light (natural as well as artificial) causes colours to fade and the paper to discolour and, in some cases, become brittle. Works of art on paper, such as watercolour paintings, Japanese prints with coloured inks, and drawings executed in iron gall inks or felt tip markers, are susceptible to fading. Light damage cannot be reversed. Avoid hanging your artwork where it may be exposed to sunlight from windows or skylights. Use curtains, blinds, or shutters in rooms where you hang your artwork. Consider framing artwork behind glazing material (glass or plastic) that filters ultraviolet light.

Also avoid displaying or storing your works of art on paper in either basements or attics where temperatures and humidity levels fluctuate. Paper absorbs moisture quickly. High relative humidity causes paper to swell and expand. The paper will appear wavy or, in the worst cases, wrinkled. When works on paper are exposed to prolonged periods of high relative humidity, they are vulnerable to increased rates of chemical degradation and to mould growth. Certain conditions, such as foxing (reddish brown spots on the surface of the paper), may become more pronounced. Low and fluctuating levels of relative humidity may be harmful to vulnerable media. Archival-quality matting, framing, and protective enclosures will protect works on paper from the effects of increased relative humidity for a short period of time.

Heat speeds up chemical reactions that lead to the degradation of paper. Avoid spotlights, and hang prints and drawing away from radiators or heating ducts.

Paper is absorbent, taking in any liquid or gas that surrounds it. Air pollutants are sources of acidity and will have a negative effect on paper and pigments. Acids from outside sources, such as poor-quality framing materials, can migrate to paper, leading to its discoloration and degradation. Paper is also harmed by contact with glue, rubber cement, pressure-sensitive tape, and masking tape. Paper clips can leave rust marks and self-adhesive, removable paper notes leave a bit of residue on the surface that can attract dirt and grime. Avoid materials that are sources of contaminants.

Some artworks are composed of materials that, due to their chemical composition, are inherently unstable and will degrade rapidly. Conservators refer to this as "inherent vice." Wood-based papers and iron gall ink are two examples of materials with inherent vice. Wood-pulp paper degrades because of lignin, a component of the woody tissue of plants. It forms acidic compounds that break down paper fibres. Iron gall ink is made from oak galls and ferrous sulphate that, over time, emits sulphuric acid and destroys the paper on which the ink is printed. Storage or display in low temperature and relative humidity may reduce the rate of degradation.

Certain insects and rodents like to feed on paper. The most common insect enemies of paper are silverfish, book lice, and bookworms. They are attracted not only to the paper but also to certain media such as pastels. If the surface of your artwork looks abraded, it is likely you will find evidence of silverfish. Occasionally, squashed insect bodies may be found on the surface of the paper or in the frame itself. Insects prefer a cool, dark, moist environment, which is another reason you should avoid storing works of art on paper in either basements or attics. The best defence against these pests is good housekeeping.

Matting and storage

Matting provides both support and protection for works of art on paper. Window mats offer space between the image and the glazing in a frame. Use four-ply archival matboard (acid-free or buffered). Japanese paper hinges are recommended for attaching the artwork to the matboard. Small to medium size works of art need only two "T"- shaped hinges at the top (consult CCI Notes 11/5 Matting Works on Paper for more information). Avoid using glue or tape to attach the hinges to the artwork. Conservators use wheat starch paste (a recipe can be found in CCI Notes 11/4 Wheat Starch Paste).

Some unframed artwork on paper can be stored in acid-free paper folders. You can make your own folders from acid-free paper (for directions, consult CCI Notes 11/1 Making Protective Enclosures for Books and Paper Artifacts). For long-term storage, these folders can be placed in acid-free boxes that have lids. If acid-free protective enclosures are not possible, the artwork may be interleaved with acid-free tissue. Cut acid-free tissue to fit the inside dimension of the storage container and place a sheet between each piece of art.

Pastel, chalk, or charcoal artworks in good condition should be matted and framed. These works can be stored horizontally on shelves or in drawers. Do not use Mylar or plastic folders, sleeves, or protective slip sheets on artworks with media that could be easily crumbled or rubbed off. A static charge can build up that may lead to the charcoal or pastel being "pulled" from the surface.

Archival storage boxes are available in acid-free lightweight card stock with reinforced corners. Professionals often use what is known as a Solander box. Made with a plywood frame, these boxes have acid-free archival boxboard tops, bottoms, and shoulders. They are covered in cloth, lined throughout with acid-free paper, and incorporate a polythene barrier between the plywood frame and the acid-free shoulder. Avoid using everyday cardboard boxes for storage — these are made from wood pulp and, because they are acidic, may damage the artwork.

Cleaning and repairs

Cleaning and repairs are best left to a paper conservator. It is far too easy to damage works of art on paper through inexpert treatment. If your artwork has signs of mould, consult a paper conservator. Mould not only poses a hazard to the art, but it can also be very harmful to people.