In Perfect binding the signatures are folded individually and stacked along the common fold, which forms the spine of the booklet.

A signature is a press sheet that is folded to form the pages of a booklet in sequential order. Each signature in a booklet is folded in the same way. The Perfect binding process is more involved (the spine must be roughened to flatten before it is glued to the cover) and tends to require a larger gutter. In Perfect booklets, creep is not a factor.

The following illustration shows perfect, left-edge binding imposition for a 12-page document:

1	Signature 1
2	Signature 2
3	Signature 3

The following illustration shows how perfect signatures are folded individually, and how the signatures are joined together at the common fold:

1	Signature 1
2	Signature 2
3	Signature 3

The following illustration shows how the signatures are joined together at the common fold for the perfect, left-edge binding booklet: