The Central Problem with Maps
Historical maps are typically large — often exceeding A0 or even larger formats. Most private collections include maps that have been rolled or folded for storage over many years or decades. Both conditions cause damage: rolling under tension stresses fibres at the inner and outer surfaces of the roll; folding creates permanent creases where fibres have broken along the fold line.
Unlike books, maps cannot simply be shelved upright. Their format demands a different approach: horizontal flat storage with appropriate interleaving is the established method for collections of any scale.
Flat Storage: Drawers and Portfolios
Flat storage drawers — shallow drawers in a plan chest — are the standard solution in institutional settings. For home collectors, flat storage can be achieved with:
- Plan chests — metal or wooden flat-file cabinets with shallow drawers, available second-hand from architectural or design studios.
- Oversized acid-free portfolios — folders larger than the map, tied closed with cotton tape, stored horizontally on a shelf or under a bed.
- Custom flat boxes — made from lignin-free board to a specific size, providing a rigid outer shell around a folded-free stack.
Within any flat storage, sheets should be interleaved with unbuffered acid-free tissue if the collection contains maps with coloured inks or watercolours, or buffered tissue for plain paper. No more than around twenty sheets per drawer keeps weight manageable and reduces the risk of mechanical damage when retrieving individual items.
Dealing with Already-Rolled Maps
A map that has been stored in a roll for an extended period cannot be unrolled quickly without risk of cracking. The standard approach is gradual humidification — increasing RH in a closed box over several days, then very gently unrolling the map while it retains slight flexibility. This process is straightforward in description but carries risk in practice; for valuable or fragile items, a paper conservator should carry out this work.
For maps that are stable in their rolled condition but you wish to move to flat storage, rolling them loosely around a wide-diameter tube (minimum 10 cm, preferably larger) wrapped in acid-free tissue is an intermediate step that avoids forcing flat storage prematurely.
Prints: Additional Considerations
Prints — lithographs, etchings, woodcuts — often have higher value per sheet than manuscript maps and may include delicate media such as hand-applied watercolour washes. The same flat storage principles apply, with some additions:
- Prints with raised or embossed surfaces (dry-point, engraving, relief prints) should not have interleaving placed directly on the printed surface. Use a mat or spacer to lift the tissue away from the image area.
- Prints framed behind glass present a separate problem: condensation on the inside of glass during temperature swings causes direct moisture contact with the paper surface. Framed prints in Polish homes should have a spacer between the glass and the print surface.
Handling
Clean, dry hands are sufficient for handling most paper maps and prints. Cotton gloves are sometimes recommended but can reduce sensitivity and increase the risk of mechanical damage from fumbled handling — a considered, deliberate approach with bare clean hands is often preferable. Never handle paper near food, liquids, or in damp conditions.
Support large-format maps from beneath when moving them flat. Allowing a large sheet to hang vertically from one edge without support stresses the paper along the upper edge and can cause tearing.
Light and Display
Ultraviolet light accelerates fading in coloured inks, watercolours, and organic-based printing inks. If maps or prints are displayed rather than stored, UV-filtering glass or acrylic reduces long-term exposure. Displayed items should be rotated with stored copies where possible. Direct sunlight, even briefly, causes measurable fading in sensitive media.