Storing Books

Stable conditions are as important as the precise levels of temperature and humidity themselves. A temperature of between 16ºC and 18ºC, and a relative humidity of around 50-60% are recommended. So next time you are shivering in the library, remember that the conditions are designed for the long-term residents.

Books do not like damp or dry conditions. Insufficient moisture causes a book's natural materials to become brittle; pages weaken and are easily torn. With old books, bindings deteriorate and crumble if the conditions are too dry. Paper also deteriorates rapidly under extremes of heat or moisture. A damp environment will encourage paper to cockle and this literally opens books to attack especially from mold.

Light fades inks and dyes and generally accelerates the decomposition of a range of printing materials. The ultraviolet (UV) component of light is the source of this damage. Leave a book open and exposed to strong sunlight and it will show signs of discoloration or fading in a few days. So windows and strong lights need to be carefully planned in a library.

Handling

Never remove a book from shelves by pulling on the top of the spine. This is a book’s vulnerable area. To take a book from a shelf, reach over the top of the book, ideally all the way to the front edge and tilt it back until enough of the sides protrude to provide a handhold. Then, ease the adjacent books apart and lift, rather than slide, the book upwards to withdraw it. When a book is carelessly pulled from a shelf, the boards or covers drag against neighboring volumes.

Always ease a book open. The paper and binding both take a moment to respond. Some book spines will be stiff, so must not be forced open beyond the point of resistance. This may be felt at just 90 degrees. The forced flattening of any book to make it lie flat will certainly damage it, which is why many libraries do not allow you to photocopy books but provide a service from people trained to handle books. Early paperbacks are vulnerable and the glue used in perfect binding can easily snap.

Never lick or dampen your fingers to turn a page. Moisture makes a mold-friendly medium and distorts the paper. 

Shelves and Storage

It is conventional to store books upright on some kind of shelving system. Because so many books have information on their spines, shelves serve as a display system too. Upright storage for most books means that they are not supporting the weight of anything other than themselves.

Upright storage requires enough books on each shelf to hold them vertically. Tightly packing the books increases the friction when they are removed or replaced, so increasing the possibility of damage. Some book-ends might be useful to allow books to stay vertical when books are removed.

Smooth-surfaced shelving materials will abrade books less than material such as natural wood. Books that are shelved too loosely may tilt and eventually become distorted. Bookends, or a few volumes laid horizontally, keep the other volumes upright on partially filled shelves. 

Large or heavy books are better stored on their sides. If they are stored vertically, the pages can pull them away from the spine. However a stack of such books cannot be more than a few books high to avoid stress on those at the bottom.

The space above the book on a shelf should be enough to allow a hand to reach over the top to extract a volume without having to tug at the spine. If shelves are too shallow the books overhang, risking mechanical damage and distortion. If the shelf is too deep it attracts dust, cups of coffee and other unsuitable material. 

Space around the books is also important to allow air to circulate. Do not overlook the space behind the books. If shelves are attached to an outside wall, there must be a space of at least 5cm to allow the moisture that penetrates the wall to be carried away rather than absorbed by the pages. Tape a plastic bag to the wall if you want to check how much moisture is getting through. 

It is ideal if the space above the book is enough to let you run the vacuum cleaning tools over the books once in a while to remove dust. 

So...

Books like a little bit of attention when they are sitting on the shelves so do have a rummage along the shelves from time to time.

Source: http://www.writersservices.com/wbs/care_storing_books.htm