Coil Binders — Punching for Plastic Coil

Thick books bind more easily with less coil running through them. They also need a thicker gauge coil to handle the weight of a heavier book. A 30mm book looks better with a 3:1 pitch than with a 4:1 pitch. If binding thick books, you would want to use a bigger round or oval hole. If you use a bigger hole, they will be too close together on a 4:1 pitch.