The Conservation and Care of Old Maps and  Prints

Grace Art Conservation is a division of Grace Galleries, Inc. Antique Maps and Sea Charts, and in our studio in Cundy's Harbor, Maine we not only restore oil paintings, but we examine and do basic conservation treatment on works of art on paper that are sold through the Gallery. In the following paragraphs we will explain initially what causes wear on old maps and prints and then show ways to preserve and care for them as fine, historical works of art on paper.

Section 1. Maps and Prints.

1. Paper as support

As anyone who has bought old maps and prints knows, after examining them, that although the image may still be beautiful, the paper on which it was engraved shows signs of wear and aging. Paper is a fragile commodity and over hundreds of years, due in part to mishandling and improper storage it can become stained, frayed or torn at outer edges and weakened at folds if it was bound into a book or atlas. From the 16th to the early 19th century maps and prints were engraved on handmade rag paper which had a strong fiber content as it's base, whereas in the 19th century, at the height of the Industrial Revolution, publishers began using machine-made paper which was cheap and readily available and made from a wood pulp base. While the early rag paper had little or no acid in its content, the later wood pulp paper was heavily acidic which over time made the paper brittle, stained and yellowed at the folds. (Click on photo for larger view). This is probably the most important reason why the early engravings have survived in much better condition than their later machine-made counterparts. Another reason why early maps (pre 19th century) have survived is that they were valued by their owners far more than maps are today and often kept in libraries and government institutions and only brought out and displayed on special occasions for important dignitaries, scholars, clerics and visitors. The less a map is handled, the better its chance of survival as even the cleanest hands have oils and body chemicals that can be transmitted to the paper with detrimental effect.

2. Sea Charts

Early sea charts present a different problem as although they were engraved on rag paper or its equivalent, and often backed with a linen fabric, they were subjected to all the rigors of life at sea in the chartrooms of early sailing ships. Coffee, oil and water stains are common on old charts, as well as tears and abrasions due to mishandling by sailors in rough seas. They were also folded and refolded or rolled tightly, when damp, to fit into sailor's lockers or sea bags which caused soiling and staining to sink even deeper into the paper surface.

3. Mold and Foxing

Mold often called foxing is a series of brown dots that appear on many old maps that have been stored in damp, humid attics or storerooms over a long period of time. (Click on photo for larger view). Foxing is a fungal growth that grows on old paper and books if the relative humidity is greater than 65% over a prolonged period of time and can ultimately destroy the cellulose fiber in the paper if left untreated. As many early maps came out of books and atlases, which were often stored after use in boxes and closets where the air was still, the mold spores in the air could attack the paper particularly feeding on any acid inherent in the book and paper contents.

4. Worms (lava)

Just as mold spores can attack paper, so can worms (larva) which eat their way through the paper causing small holes in a map's surface. Worm holes are more common on old sea charts where the chart is exposed to the open damp atmospheric conditions at sea, where the larva can breed and feed on the paper.

5. Offsetting

Another defect found on old maps and prints is called “offsetting” where the text or image from a previous page shows through onto it's neighbor in a book or atlas. In the early days of printing the oils in the inks took a long time to dry and if the map or print was not completely dry before being bound into a book or atlas, sections of printed matter could transfer onto the back of a following sheet when pressed against it in the bound volume.

6. Varnishing & shellacking

In the 19th century large wall maps of States, Counties and Towns, became popular for schools, town offices and for display in the larger houses of the period. They were fitted with poles at top and bottom and backed with a linen fabric. They were also shellacked in what was considered at that time, a way to protect the surface of a map from damage due to touching and handling by schoolchildren and others tracing their streets and houses and land boundaries on the maps. Unfortunately, over time the shellac dried out and cracked, causing the map surfaces to lift from the backing which became torn and frayed. In many cases the poles fell out as the backing gave way and once their popularity waned, their owners rolled them and stored them in attics and closets, where their deterioration continued, attacked often by mold spores, worms and damp. Restoring these maps is extremely difficult as the old shellac has to be removed before any conservation work can be attempted.

CARING FOR YOUR MAPS AND PRINTS

Bearing in mind the basic concerns listed above, there are a number of things a map collector can do to preserve a collection without resorting to major conservation methods, which can be costly and time-consuming, although if a map or print has major tears or staining, it should be treated by a recognised paper conservator.

Helpful hints and do's and don'ts!

1. Tape

Never use ordinary Scotch Tape to repair even minor tears. In our studio we use a product called "Document Repair Tape" which is an archival acid free & lignin free mending tissue that is very thin yet strong. It is non-yellowing, unlike Scotch Tape which yellows with age, and virtually disappears when burnished. Its primary function is the repair of tears & other damages to documents, maps, prints and works of art on paper.

2. Erasers and Cleaning

Never use an ordinary eraser on the surface of maps and prints to remove soiling, as erasing tends to lift the inks off the engraved surface. In our studio we use a product called "Document Cleaning Pad," which is non-abrasive and contains a super soft grit-free powder that absorbs surface soil and finger prints.

3. Adhesives

Never mount a map or print onto a backing board with an adhesive, as adhesives can destroy the delicate fibers in the paper and cause staining. It also causes loss of value in the map especially if the map is a rare or scarce item.

4. Handling

If possible when handling maps and prints make sure your hands are clean and only handle a map by its outer margins. As noted above, body oils from fingers can be absorbed into the paper causing soiling. Professionals use white cotton gloves when handling prints, but as long as you use care when handling the item and don't touch the surface image, you can avoid the "white glove" treatment!

5. Storage

The only time a map or chart can be rolled is for shipping and then it shouldn't be rolled tightly, as rolling puts a strain on the delicate fibers in the paper. In our studio we place our maps in clear, archival polyester bags and lay them flat in storage cabinets. These cabinets are made especially for storage of artwork, blueprints, maps and charts and measure approximately 40"wide by 28" deep. The csbinets come in 3 or 5 drawer sizes and can be purchased from a number of art supply stores. These are basically flat filing cabinets and we recommend them for keeping your maps, charts and prints in maximum safety.

6. Framing

When framing your maps and prints, be sure to use acid-free mats and backing boards. A mat is necessary as the map surface should not be pressed against the glass. The framed map has to 'breathe' so moisture can't build up under the glass in humid or damp conditions. If for personal reasons you prefer not to use a mat, 'spacers' can be placed between the map and glass which act as buffers instead of a mat.

Glossary of Map Terms

20 West Cundy's Point Road
Harpswell, ME 04079
Phone (207) 729-1329 - Fax (207) 729-0385
E-mail jackie@gracegalleries.com