Plastic comb binding is a traditional and economical binding method that uses PVC plastic comb spines with round rings that are spread apart and then closed around a stack of paper, binding the book. The rings fit into rectangular holes and a standard letter size sheet will use 19-ring combs. Along with the economical price benefits, plastic comb binding is preferred for applications such as cook books and manuals that will be stacked on a shelf because of the ability to custom print on the spines. They can also be simply re-opened and closed to add and remove pages for frequently edited books. Binding101.com offers many comb binding machines and systems, from low volume to industrial, to meet any need.