Close up detail of the pin stripping on a 1937 Plymouth coupe custom hot rod. Pin striping (pinstriping) is the application of a very thin line of paint or other material called a pin stripe, and is generally used for decoration. Freehand pin stripers use a specialty brush known as a pinstriping brush. The goal of pin striping is to enhance the curves of the surface, and the lines are generally of a complementary color. In any other form of decorative pin stripes, the goal is the same.