The signatures, or folded sheets of paper that make up a book, are sewn together to form one text block.

<TEXT BLOCK>

The interior pages of a book, sewn and/or glued together, make up its text block. Single sheets of paper may simply be glued together to make a text block, but more often the pages are actually sets of folded sheets called signatures. The folded signatures are sewn together, then glued to form the text block.

A sewing frame is used to hold the signatures as they are sewn into a text block.