Pressure on the rounded back will weaken a book in the most vital part.
DO NOT—
use too much paste.
use Lepage's glue or any mucilage.
use cloth strips in a book except at the joint.
paste heavily up the back unless a very old and not valuable book.
overmend on a book which will ultimately be bound.
allow loose pages to be slipped up in the book above the top of book.
use heavier paper for patching than paper of book.
ALWAYS—