Fold
This standard fold is the most common, and is used in the production of multi-page documents.
This fold is combined with stitching to create brochures and booklets. This fold works in multiples of 4 printed pages, which means that anything you produce to be folded in this way must be in multiples of 4 pages.
Roll fold
There are 6 printed pages that fold into each other. Looking at the inside, the right hand panel folds in first and then the left. The panels are fractionally different widths to allow them to comfortably nest inside each other.
This is a common fold used for small brochures.
Z fold
There are 6 printed pages that have 2 parallel folds that go in opposite directions which, when seen from above, resemble a z shape. Each panel is the same size.
This can be used effectively on documents that have more pages (in multiples of 2). 8 and 10 page z fold brochures are common.
Gate fold
In the gate fold the left and right panels are half the width of the back panel and fold in towards the centre to meet in the middle (2 parallel folds).
This can then be folded in half vertically (3 parallel folds) to form a double gate fold , although the left and right panel in this case would then be less than half the back width to allow them to nest comfortably inside each other.