Buckstitching is a technique used in leathercraft for securely joining two or more pieces of heavy leather along a seam. It is a simple, durable technique. Buckstitching is performed using a pronged metal tool that leatherworkers call a "buckstitch chisel" that has between one and five (or more) cutting tips. The chisel is held over the leather pieces to be joined, and is then struck with a mallet until the chisel penetrates all of the leather and produces what are called lacing slits. This is repeated along the entire seam. Next, a special leatherworker's needle is used to thread a wide sturdy lace back and forth through all of the slits.