Ways of folding
Layer or parallel fold (4 pages)
In everyday language this is also called "fold". As the name suggests, the paper is folded only once in this way of folding.
Letter-fold (6 pages)
As the figure shows, the paper here is "enveloped". This folding forms two parallel folds. Through the closed edge formed by means of this method of folding, parts folded in this way can be mechanically enveloped.
Cross-fold (8 pages)
In the everyday language this fold is often called simply as "star break" because the folds are in an angle of 90° with respect to each other. Mostly, two folds are folded, but also more are possible. Thanks to the closed egde a mechanical processing is possible.
Leporello, or Z-fold (8 pages)
In this way of folding the paper is folded alternately to the front and to the rear. The Z-fold consists of two or more parallel folds. For mechanical enveloping the Z fold is unsuitable because it has no closed long side.
Two fold window fold, or gate fold (6 pages)
As the figure shows, the paper looks as if it has two wings like a window or an altar, hence the name. This way of folding has two parallel folds. This way of folding looks elegant and is often used in invitations and the like.