Preserving Columbia’s Library Materials Part 1

What this presentation covers Part 1: Why materials deteriorate. Part 2: Shelving materials carefully. Part 3: Handling materials carefully. Part 4: Identifying and preventing damage.

Why materials deteriorate. Chemical deterioration from the materials themselves and the environment they’re stored in. Physical deterioration due to wear and tear. Disasters.

Chemical deterioration Everything organic deteriorates. Books are made of organic materials -- paper, cloth, leather.

Paper fibers magnified. Long strands of cellulose matted together like felt. Very flexible when new.

Handmade paper Before the middle of the 1800s, paper was made by hand. Paper was made of cotton and linen fibers -- long, strong fibers that can last hundreds of years. No harmful chemicals were added.

Making paper by hand.

Handmade paper like this has lasted for centuries. It stays flexible. It doesn’t turn yellow.

Modern paper is made by machines.

The usual material is wood pulp -- contains elements that slowly turn into acids. Paper-makers add acidic chemicals to whiten paper. Acid breaks up paper fibers into short pieces. Paper becomes yellow, brittle, and breaks easily.

Acid-free paper It is possible to produce acid-free paper that will last hundreds of years, even from wood pulp. Paper makers can add chemicals to neutralize the acid and keep paper flexible.

Many US and European publishers use acid-free paper. Often they put a note on the title page verso. 

Chemical deterioration is speeded up by High temperature -- over 70  High humidity -- over 50% Fluctuating humidity Light Pollution

High temperatures A rise in temperature of 10 degrees Celsius makes chemical reactions happen twice as fast. The recommended high temperature for books is 70 degrees.

High humidity Speeds up chemical deterioration so that paper becomes brittle faster. Encourages insects and mold.

High humidity Encourages insects. These covers were chewed on by roaches.

Humidity over 50% encourages mold.

Fluctuating humidity When humidity keeps switching quickly between high and low, materials like vellum expand and contract as the air gets wetter or drier until they warp and break.

Other environmental sources of damage: Light Pollution

Light causes damage due to fading.

Curtains and light timers in stacks reduce damage.

Pollution Gases given off by car exhaust are acidic and help paper to become brittle. Dirt gets on book covers and makes a mess.

Physical deterioration is caused by Wear and tear from heavy use Carelessness Poor shelving and handling Photocopying

Books wear out due to heavy use

Poor shelving Lack of bookends can cause permanent damage due to lack of proper support.

And careless handling

Photocopying causes damage

Disasters cause damage Every year fire, floods, storms, earthquakes, and disasters due to poor facilities management in libraries damage or destroy thousands of books and other materials.

Floods and leaks can devastate libraries.

Fire are even worse. The Los Angeles Public Library fire of 1986 damaged over 1.3 million volumes, and destroyed 370,000.

Fire damage Little or nothing may survive.

Water damage Water causes books to swell and warp. Books with glossy paper stick together in a solid block if they are not dried immediately after getting wet.

Mold Even damp books can grow mold in just a few days.

Columbia’s Annex shelving collapse in caused by poorly installed shelving.

Slide show continues. Go on to Part 2: Shelving materials carefully. If you have questions, send to