Coil binding

Coil binding, also known as spiral binding, is a commonly used book binding style for documents. This binding style is known by a number of names including spiral coil, color coil, colorcoil, ez-coil, plastic coil, spiral binding, plastikoil and coilbind. Documents bound with helical coil (usually called spiral coil) can open flat on a desk or table and offer 360 degree rotation for easy note taking. This binding style is durable and is often used for documents that need to be mailed. Spiral coil binding spines are also available in more colors and sizes than other binding styles.

The most common hole pattern used with coil binding is a 4:1 pitch hole pattern (6 mm outside the US), which has four holes per inch along the binding edge of the sheets of paper. The holes for this style are usually either round or oval shaped and depending on the size and spacing of the hole pattern, there will be 43 or 44 holes on an eleven-inch binding edge. Supplies for binding documents with 4:1 pitch spiral coil are available in sizes ranging from 6 mm up to 50 mm in diameter. This allows for binding documents that are up to two inches thick.

A .2475-inch pitch spiral is similar to the 4:1 pitch plastic spiral; the difference is .0005 inch per loop. This pitch was designed to slightly modify the 4:1 pitch punch pattern to perfectly center 44 holes on an 11-inch binding edge and still use the 4:1 pitch coil. This makes it easier to automate the coil insertion process. Some manufacturers make the coil specifically in the .2475-inch pitch to make it even easier. Coil is available in 6 mm to 30 mm in .2475-inch pitch.

Although not as common as 4:1 pitch coil, some printers and binderies use 5:1 pitch coil. With five holes per inch, 5:1 pitch coil is more tightly wound and provides a neat and tidy appearance. However, the tight spacing of the coil and the smaller size of the holes used by this pattern limit the size of spines that are available. Spiral coil with 5:1 pitch is available in diameters ranging from 5 mm up to 25 mm. This means that documents larger than one inch thick cannot be bound using this hole pattern.

Spiral coil with 3:1 pitch is less common than either 5:1 or 4:1 pitch coils. It is designed for the hole pattern used in wire binding or with GBC Proclick. Three to one pitch spiral coils are slightly easier to use for large diameter books because there are fewer holes to insert the coil through. Supplies for this hole pattern are available in sizes ranging from 6 mm up to 56 mm.

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Wikipedia