2. If the book is to be used constantly leather is essential; if occasionally only, leather is an element of weakness.
3. All books that receive hard usage should have end papers and fly-leaves guarded with cloth. If sewed regularly the first and last signatures also should be guarded.
4. Saw cuts should not be deep.
5. The book should be flexible and stay flat wherever opened. (This is not always possible in the case of overcast books or books printed on stiff, brittle paper.)
6. When the book is lying flat the top should remain flat. When standing on end the sections should not separate slightly at the back.
7. The book should feel firm and compact to the hand.
8. When opened the volume should not make a crackling noise due to too much glue on the back.
9. The book should have a well rounded back and the cover should fit well at the joint. Flat backs are not desirable.
10. Margins should be wide and cut straight. Periodicals should not be trimmed so that printing on covers or advertisements is cut off.
11. The book should have French joints.