A pintuck is a fold of fabric that has been stitched to hold it in place, much like a pleat. Pintucks give a decorative effect to the fabric, creating a visual line at a chosen point. They are often seen in vintage clothing, but they can be used to create a very modern look as well.
Usually, this type of fold is very narrow, although sometimes wider pintucks are used on pillows or upholstery. A wide pintuck can be folded flat against the base fabric. Typically each fold in a group is the same size, although a change in size can be used to create special visual effects. Pintucks are often spaced evenly across the fabric.
Pintucks are typically created in a group, with each tuck is parallel to next one. They are often placed on the bodice of a blouse or dress, where they usually have a vertical orientation. Another popular pattern is to place each pintuck so that the lines form a ray. Sometimes a single tuck is used to create a simple line, and that line can curve and wander randomly across the surface of the fabric, even crossing earlier lines.
A pintuck can be placed so that each end is enclosed in a seam, or it can be placed like a pleat so that one end is in the middle of the fabric. In that case, the pintuck must be tied off so that it will not come unstitched. A group of open-ended pintucks can control fullness in the finished object, just like a dart.
For many years after basic sewing was done on a sewing machine, hand sewing was still needed to make a pintuck, because controlling the size and spacing is so difficult. Today, however, many sewing machines have a special foot that makes controlling both the width and the spacing much easier. It is easier than ever to experiment with the many visual effects that can be created by a simple pintuck.