Bi-fold brochures are flyers that are printed on both sides and then folded in half, usually with a single fold down the centre. Therefore, an A3 sheet printed on both sides and folded vertically to create two A4 sheets is called 4pp A4.


Tri-fold brochures are flyers that are printed on both sides and folded into thirds. They are usually printed on an A4 (297 X 210mm) and folded twice to a 6pp DL (because the finished size is DL and each folded panel is counted as a page).


Cross-fold brochures are flyers that are folded vertically and then horizontally. This can happen several times (see crush fold below). A common example of this is an A3 sheet printed both sides that is folded in half, and then half again to creates an 8pp A5 brochure (cross fold).


Crush-fold/map-fold brochures are when you fold a cross-fold brochure over on itself, for example an A3 sheet printed both sides, tri-folded and then folded over again to create a 12pp DL brochure.


Roll-fold brochures are multi page folded brochures, opening outwards it rolls open, so that all the folds are in the same direction. Where the brochure is folded inward at one end it is then folded inward again and again.


Concertina-fold brochures, also known as z-fold or zig-zag fold, are simple zig-zag folds with 6-panels and two parallel folds that go in opposite directions. Each panel of the concertina fold is about the same size.