Bifolds, Z folds, Accordian folds and Booklet or French folds have all evenly sized panels. Many of the more common folds are shown in the following diagrams. Some folds require "short panels" to allow the finished piece to remain flat otherwise the folded in panel will "dog ear" and not be a good fold. The short panels are identified on the pictures below. The amount of trim for the short panels will depend upon the weight and type of stock used in your project, but a safe measurement is 1/16th of an inch.
Tri-fold or Letter fold
Tri-folds are commonly used for marketing events, services or products. The panels fold in on each other to form the finished size. The three panels do not have the same width since you need to compensate for the thickness of the paper in the fold and tolerances of the folding machine. For an 8.5″ x 11″ tri‑fold brochure or pamphlet, make part 3 which folds to the inside 3.625″ wide while the 2 other panels are 3.688″ wide.
You can use the guides in our templates available, open the template in the application to see the fold lines in addition to trim and bleed lines during the design of the document. Keep in mind that panel 2 is the back cover. The user first sees the front cover (panel 1) and then upon opening panel 3 so these two panels should have a matching or consistent style.
Double Parallel or Gate Fold
When doing a 4 panel double parallel fold or 4 panel gate fold, two of the panels are wide and two short. Divide your width by 4 (ie, 17 divided by 4 is 4.25). Add a 32nd, or .03125, to the number to get your wide panel size (ie, 4.28125). Subtract a 16th, or .0625, from the wide panel size to get your short panel size (ie, 4.21875).
4 panel roll folds have two panels that are the largest size, a short panel, and an even shorter panel. Divide your width by 4 (ie, 17 divided by 4 is 4.25). Add a 16th, or .0625, to the number to get your wide panel size (ie, 4.3125). Subtract 3/32nds, or .09375, from that number to get the short size (ie, 4.21875). To get the final, even shorter size (the shortest size), subtract another 16th, or .0625 (ie, 4.15625). This actually makes the difference between the two large panels and the short panel 3/32 instead of a 16th, but that's only a 32nd of an inch difference.