When it comes to punching for plastic coil there are quite a few options for pitch and shape of the hole. By far the most popular pitch for coil binding is 4:1. Very few new machines are sold without a 4:1 die, and some of the manufacturers of plastic coil have stopped manufacturing the 5:1 pitch. The three most popular types of hole patterns with 4:1 coil are the .250, .248 and the true oval pattern. The main difference is the size of the hole and the shape of the hole. The true oval pattern is the easiest type of hole for coil insertion, but is generally the most expensive die to purchase. The .248 hole is larger and much easier than the traditional .250 hole pattern. If your copier has inline punching capabilities or you purchase your paper pre-punched, please check the die pattern before your order your machine. Need more clarification?, please give one of our coil experts a call.