A pintuck is a thin fold of fabric that has been stitched to hold it in place. Pintucks are a versatile detail you can add to the simplest of garment designs. But sometimes wider pintucks are also used on pillows and upholstery.
Pintucks are often spaced evenly throughout the fabric, usually created in group, with each pintucks laid parallel to each other.
It is often used on the bodice of a garment or dress and hence give a decorative effect to the dress. Sometimes a single tuck is used to create a simple line and that line can curve and can be placed across the surface of the fabric, even crossing earlier lines.