Do you prefer wire binding but don't have a wire binding machine? Because plastic comb binding machines require 19 holes and a wire closer, these Spiral-O wires are compatible with those devices. The spine thicknesses of these wire bindings are between 1/4" to 1", which means they may accommodate anything from 40 to 200 pages of 20lb paper. Black, the go-to for professional document binding, looks great with any hue. Start binding right now using Spiral-O.