Girl Wearing A Kilt

Pleats can be arranged relative to the pattern in two ways. In pleating to the stripe, one of the vertical stripes in the tartan is selected and the fabric is then folded so that this stripe runs down the center of each pleat. The result is that along the pleated section of the kilt (the back and sides) the pattern appears different from the unpleated front, often emphasising the horizontal bands rather than creating a balance between horizontal and vertical. This is often called military pleating because it is the style adopted by many military regiments. It is also widely used by pipe bands.
In pleating to the sett the fabric is folded so that the pattern of the sett is maintained and is repeated all around the kilt. This is done by taking up one full sett in each pleat, or two full setts if they are small. This causes the pleated sections to have the same pattern as the unpleated front.
Any pleat is characterized by depth and width. The portion of the pleat that protrudes under the overlying pleat is the size or width. The pleat width is selected based on the size of the sett and the amount of fabric to be used in constructing the kilt, and will generally vary from about 1/2" to about 3/4".
The depth is the part of the pleat which is folded under the overlying pleat. It depends solely on the size of the tartan sett even when pleating to the stripe, since the sett determines the spacing of the stripes.