High quality binding wires, for use with all A4 long edge spine binding (or A3 short edge, for calendars or landscape documents). 3:1 wires are a closer loop wire than 2:1 pitch, with 3 loops per inch, giving a more attractive and secure final finish. 3:1 pitch wires are available from 5.5mm (for just a few sheets of paper, or a calendar) up to 16mm, for up to 135 sheets of 80gsm paper. For anything above this size you will need to buy and use 2:1 pitch wires, which go up to 38.0mm.

3:1 pitch means 3 punched holes per inch. (34 Loops)