Wire-O binding is preferred above all other book binding methods due to the professional and clean metallic finish it provides. Sometimes called double loop or double-o, wire binding uses a continuous hinge of paired loops to bind books together. This modern binding method provides security as it cannot be taken apart without damaging the wire binding spine. Book binding wire also lets your book lay flat and the sheets turn a full 360°, making it a great solution for calendars and notebooks.
Wire binding equipment is available in two configurations including a 3:1 pitch and 2:1 pitch. The pitch is measured by the number of holes per inch; a 3:1 features three holes per inch and a 2:1 features two holes per inch. 3:1 pitch machines give you the capability to bind using wire sizes 3/16” through 9/16”, which is a maximum book thickness of about 120 sheets of 20# bond paper. 2:1 pitch gives you the capability to bind using wire sizes 5/8” through 1-1/4”, which is a maximum book thickness of about 280 sheets of 20# bond paper. Binding101.com now offers special 2:1 pitch small wires in many colors, giving you the full range of wire sizes from 3/16" to 1-1/4".