Preserving Rare Books

Most damage to books in private hands is caused not by neglect but by ordinary domestic life: a radiator, a sunny window, a shelf that is slightly too narrow, and a habit of pulling volumes down by the headcap.

Shelving

Shelve books upright, of a size with their neighbours, supported on both sides so that none leans. A leaning book distorts permanently within months.

Do not pack a shelf tightly. There should be enough room to remove a volume without force.

Large or heavy folios should lie flat, no more than two or three high, rather than stand. A heavy text block standing on a weak joint will break it.

Keep books away from exterior walls, which are cooler and attract condensation, and away from radiators, fireplaces, extractor vents and direct sunlight. Metal or sealed wooden shelving is preferable to raw wood, which off-gases acids; if wooden shelves are used, seal them and line them with an inert barrier.

Leave a gap between the back of the book and the wall so that air can move.

Handling

Remove a book by pushing back the volumes on either side and grasping the middle of the spine — never by hooking a finger over the headcap, which is how most torn spines begin.

Support the covers when open. A book with a tight binding should not be forced flat: use a cushion, a foam cradle or simply your hands to hold it at a comfortable angle. Photocopying a tightly bound book flat on a platen is a reliable way to break it.

Clean, dry hands are better than cotton gloves for paper, which requires dexterity; gloves reduce grip and cause fumbling. Use nitrile gloves for photographs and metals.

No food, no drink, no adhesive notes, no pens near the shelves. Mark your place with a strip of acid-free paper, never with a paperclip, a pressed flower or a letter.

Environment

The single most useful thing an owner can do is keep conditions steady. Fluctuation is more damaging than a constant figure slightly outside the ideal.

Aim broadly for a cool, stable temperature and a moderate relative humidity — conventionally in the region of 45 to 55 per cent. Below roughly 40 per cent, leather and parchment become brittle; above roughly 65 per cent, mould becomes a real risk.

Avoid lofts, cellars, garages and any room subject to sharp daily swings. A cool interior room on an upper floor is usually the best a house offers. An inexpensive hygrometer will tell you more about your collection's prospects than any amount of good intention.

Keep light levels low, and keep books out of direct sun, which fades spines within a single summer.

Pests

Check regularly for silverfish, booklice, woodworm and rodents. Look for frass, small exit holes, grazed surfaces and cobwebs. Keep the area clean and dry, do not store cardboard or food nearby, and isolate any newly acquired book showing signs of infestation until it has been inspected.

What not to do

Do not oil or dress leather. Leather dressings were once routine and are now discouraged: they darken bindings, attract dust, and can migrate into the paper.

Do not attempt to repair a binding. No adhesive tape of any kind, no glue, no rubber bands, which perish and stain.

Do not clean pages with erasers, bread or solvents.

Do not laminate, and do not use polyvinyl chloride sleeves.

Do not attempt to treat red rot — the powdery deterioration of some nineteenth-century leather — beyond housing the volume in a protective box. Consolidation is a conservator's task.

When to call a conservator

Active mould, insect infestation, water damage, a detached board, a broken text block, ink corrosion, or any volume of importance that needs stabilising. Ask us for a referral; an early consultation is almost always cheaper than a late one.