Number 3    Looking after Antique Maps & Prints      Compiled by Hans Kok

A.     Purchase and Transportation

Never buy a framed map without looking at it unframed.  Hold the map against the light and look at it from the back.  This way it will be easier to detect flaws such as restorations, cut margins, holes and other defects.  Do not fold maps, except along the original centre-fold, if the map has been bound into an atlas.

Ensure the map/print is wrapped up properly:

• flat cardboard on both sides, with the cardboard larger than the map on all sides   or
• rolled and wrapped up in paper.  For better protection place rolled map into a cardboard or plastic tube.  The more brittle the map the larger should be the diameter of the tube.  Where there is old verdigris (green colour that has soaked into the paper and oxidised with age) the paper may be very brittle, and should, by choice, not be rolled at all.

Keep the receipt for future reference, including insurance matters, or note the details in a separate register for the purpose.  If purchasing maps abroad, note the prevailing rate of exchange.  Value-added Tax, Sales Tax, and Import Duty are not usually applied to maps over a hundred years old.

B.     Viewing and Handling

Lift the map using both hands, or slide it across without lifting it at all.  For repeated handling, the use of white cotton or synthetic gloves is recommended to avoid thumb marks.  Covering a map with a sheet of mylar will protect it from skin-grease.

Ensure that a well-lit, clean and flat surface is available.  This should be larger than the size of the map, and double if several maps are to be viewed together.  This ensures ample space to slide the top map off in order to view those below.

If the map has been rolled, unroll it carefully and use paperweights to hold the map flat.  Longer, lighter weights are preferable to heavier round or square ones.  Even before a weight is removed, the paper may roll up again, tearing along the edges of other weights, especially if there are already minor tears at the margins.   A rule with a heavy weight on top will prevent this.

Do not lean on the map; paper is fragile, and any protuberance under the map could cause permanent damage.  Be careful where you place magnifying glasses, etc., certainly not under the map.

Do not write on the map or map margin.  If writing is essential use a soft pencil (type 4B or softer) and write only in the margin, or on the reverse side of the map, with as little pressure as possible.  If an eraser is necessary, try and match the paper quality with the type of eraser.

Do not apply any stamps, labels, stickers, book marks to either the front or the reverse of the map.  Do not use embossing of any type.

C.     Storage

Store maps away from direct sunlight.  The best conditions are: room temperature (+13°C/55°F) and relative humidity +55%.  In general rapid changes in temperature or humidity are more harmful than gradual alterations.

In tropical climates (temperatures consistently above 26°C/80°F and humidity above 75%) de-acidification is recommended, unless a stable air-conditioned situation can be guaranteed.  Restorers specialising in paper restoration are generally able to do this.  A lesser alternative is to use a dehumidifying unit in an enclosed space.

If the map is to be hung, select a wall with as little direct light as possible.  Blue colours especially will fade quickly, other colours will lose their freshness and paper will brown.

As soon as possible place the map in a protective passe-partout, with or without a clear plastic sleeve.  The face of the map may be protected separately by using an acetate-type (or mylar) sheet inside the passe-partout.  Avoid regular plastics and polythenes, as they contain softeners which will damage the map over time.

Do not store several maps in one folder for long periods of time.  If this is necessary, do not place heavy objects on the folder (colour may transfer from one map to another, or from one side of a folded map to the facing side).

For longer periods or permanent storage, use a hinge-backed conservation mount.  These mounts are made of archival cardboard - which is completely acid free - or barrier-board, where the core material contains acid but the surface layers are acid free.  Non-acid-free cardboard browns easily; barrier board will show its brown core at the cut edge, though the treated surface will not brown.  Archival cardboard will not brown even at the cut edges.

Acid-free board is generally white or cream-coloured.  If a coloured effect is desired, any coloured board should be separated from the map by a lining or acid-free board.  Information supplied on ready-made mounts is not always reliable; also different material may have been used for the two sides of the mount.

The question of whether maps should be stored in a vertical or a horizontal position remains unanswered, with no agreement among the experts.

D. Framing

Never trim the margins of a map to make it fit a frame or passe-partout.  Never glue the whole surface to a cardboard or wooden board.  Acid free mounts should be used and the immediate backing material should also be acid-free.