Accordion pleats are narrow, vertical folds in fabric that are most commonly found on either clothing or upholstery items, such as curtains. The name accordion pleat comes from the fact that when the fabric is spread open, its appearance resembles the musical instrument of the same name — an accordion. Accordion pleats are formed by folding or creasing some of the material behind itself and hot-ironing the pleat in place. The fold typically is .125 to 1 inch (about 3.175 mm to 2.54 cm) wide; a wider pleat could be called a box pleat.
An accordion is a keyboard with an expandable bellow chamber that is strapped around the musician’s neck and played with an in-and-out motion of the arms. The bellows open and close, which is the motion duplicated by accordion-pleated material. Rarely seen in contemporary groups, the accordion is thought to have originated in some form in the ancient Far East, but is best recognized for playing up-beat European rhythms, such as the polka, and some Latin rhythms.
Just as the accordion became international, accordion pleats have also enjoyed long-lasting and nearly universal popularity. They can be seen in everything from Oriental paper fans to Scottish kilts and cardboard alphabetizing file folders. Accordion pleats have found popularity during many periods of fashion in North and South America and in Africa.
The pleating is typically done around the entire piece of material, or in groups of folds at repeated intervals as a design. All folds usually face the same direction. A much wider piece of fabric is needed than the desired end width due to the doubling of the folds.
With clothing or drapery material, manufactured accordion pleating is typically intended to be a permanent fold. After the dress, blouse, skirt, or draperies endure a lengthy period of wear or hanging, however, the pleats may need to be ironed to retain or restore their initial crisp appearance. This usually can be done carefully at home by hand, at a business that does dry cleaning or alterations, or by a seamstress. The pleats could be tacked or sewn in place if a person desires, but this will restrict the opening and closing movement, which could add less interest to the material.