FRANK MOWERY graduated from high school back (in the early '70s) when career planning was not too cut and dried a thing. Today he's not the oceanographer he thought he'd be, but that's no loss to him or to the Folger Shakespeare Library. At 24, Mowery is head of the library's department of conservation and binding.

"I guess I got into this because both my parents are librarians. I graduated high school a half-year early, and took a job in my father's library, gluing books together with no training.

"There are very few places in this country to learn fine bookbinding," Mowery says. "I wrote Bernard Breslauer (the book dealer who recently paid a record $2 million for a Gutenberg Bible), asking if he knew anyone willing to teach binding to a beginner. Prof. Kurt Londenberg of Hamburg was in his opinion the best binder in Germany, and Londenberg took me as his student."

Mowery studied six years in Germany, Switzerland and Austria, and helped in the restoration of flood-damaged books at the Florence Library in Italy, working under a grant from the Austrian government. He returned to the United States as a master binder, worked a few months at the Huntington Library in San Marino, Calif., and hired on at the Folger last year.

Karen Garlick got into the profession as accidentally as Mowery. While working for her MA in 18th-century English literature, she came to the Folger's bindery three years ago for a short spell as a volunteer, decided to stay, and now works with Mowery under a grant from the National Endowment of Arts.

Their studio, with shelves of leather and paper looming to the ceiling, smells like Miss Emily's house in the Faulkner story. The tools of the trade carry that mood back to inquisitional times. Presses, clamps, shears and vises sit on broad tables, surrounded by mutilated books which, after 500 years or more, still have a few secrets between their covers. One Latin incunabula (incunabula are books printed within 50 years after Gutenberg invented his printing press) has faded script on both sideboards.

"Pieces of manuscript were sometimes pasted over bindings," Mowery says. "In this case, we believe they're several hundred years older than the book itself." After repairs are done, a researcher will try to figure out where the scraps are from, and who wrote on them.

There's more to the binder's job than touch-up work. Besides restoration, Mowery practices fine binding, which involves disigning a unique cover for a particular copy of a book. Mowery has to put himself in the mind of the original artist, searching for the right modality. Carl Orff's "Musica Poetica," illustrated by Jonny Friedlaender, is an example.

"The cover had to be designed and executed so the binding imagery coordinated with the book's content," says Garlick. "Frank studied Friedlaender's illustrations and came up with this cover design - an abstraction of Gclef."

Mowery and Garlick do off-hours commission work, but if you have ideas about getting them to restore the family Bible, forget it unless you attach enormous sentimental value to it. Extensive repairs can run to several hundred dollars. "A large book like this one (about 18 x 24 inches) will cost $80 for the leather alone," Garlick says.

A problem common to books bound in leather in the late 18th and early 19th centuries is the so-called "red rot," an early example of shoddiness in mass-produced work.

"They took shortcuts," Garlick says. The result was leather bindings that deteriorate in humidity and air pollution.

Mowery suggets "the best you can do with such a book is tie it with twill tape (available in sewing shops) and wrap it in paper" to slow the necrotic process. But there is no hope of stopping the reaction or restoring the original leather.

The Industrial Revolution also brought a "brown, brittle paper high in wood content" which also needs careful handling, according to Garlick.

"You can feel the wood fibers by rubbing the pages between your fingers," she says. "And you'll notice it crumbles easily."

Most publishing houses today bind books with adhesive, rather than stitching them in the painstaking tradition.

"They'll show someone holding a book by one page, shaking it from side to side, to demonstrate how strong the adhesive is," Mowery says. "But there are a great many books on the market that fall apart in a few years."

He suggests breaking in a new book by opening it and gently creasing back the first four or five pages, and continuing through the book, folding larger sections of pages as you proceed. Then turn the book over and do the same from back to front.

Mowery and Garlick offer some do's and don'ts: Don't leave a large book, such as a dictionary or atlas, perpetually open; it damages the binding. Pull a book off a shelf from its middle, rather than grasping it by the top of the binding. And don't lick your fingers when turning pages.

The worst damage is done by fluctuating humidity and temperature. The ideal environment is a constant 70 degrees and 50 percent humidity, Garlick says. And no smoke - tobacco, wood or otherwise.

"The Folger was built with 'modern' air conditioning, but it was still too dry and hot in the winter, and too wet and hot in the summer," she notes."Beginning in May we're building a new extension, with a new air conditioning system, which should solve the problem."

You can give your old books a longer lease on life by treating the leather once a year with lanolin preparations available at bookbinding stores, according to Mowery. Simple maintenance is within the scope of any book owner, but where restoration is concerned, "if it's a very rare book, the homebody has limited capabilities," Mowery says.

"The Smithsonian Associates give courses in basic bookbinding about every semester," Garlick says. But, she adds, your best bet is to spend a few years with a craftsman, learning one-on-one, before you try to repair a book of any great value. In this country anyway, it's the only way to become a pro.

There are more than two dozen binderies in the Washington area. Many deal only with institutions such as schools and libraries, but some will accept custom work. For instance, the Bible Hospital ("where old Bibles never die") in Alexandria charges $25 and up to bind and restore standard-sized (about 8-1/2 x 11 inches) Bibles, and $75-100 for larger ones. The Dabney Binder in Temple Hills, Md., quotes a rebinding job at $11-30, depending on the book's size and the material used (cloth or leather). Cloth-bound theses run about $15.

Whether you're a professional or an armchair enthusiast, these make interesting reading:

"Binding and Repairing Books by Hand" by David Muir. (New York: Arco Publishing, 1978.)

"Manual of Bookbinding" by Arthur W. Johnson. (New York: Scribner's, 1978.)

"New Directions in Publishing" by Philip Smith. (London: Van Nostrand, 1974.)