In binding and finishing, the act of punching holes in press sheets, signatures, books, etc., so as to facilitate mechanical binding, commonly in ring binders or post binders. The specific punching of three holes for three-ring binders is known as three-hole drilling. Drilling is also known as punching. Drilling is often performed on special drilling devices or, when done on small quanmtities, on a common three-hole punch. When performed as a bindery operation, it is known as bindery punching.