Double loop binding, also known as twin loop binding or double wire binding, offers a simple yet elegant presentation. This option of bindery helps books to lie flat and be turned 360°.
Both spiral and double loop binding give the same impression, however there are certain differences between the two namely: thickness. And coil binding involves plastic and it is spiraled down at a slight angle to the book.
With the help of a wire-closing device, a C-shaped wire spine is squeezed into a closed circle and this option is be preferred for books such as:
Double looped books are made of individual sheets, each punched with a line of either round or square holes on the spine. The thin twin metal loops used, apart from offering an organized look, are simple, neat and delicate.
Hole patterns for smaller and bigger books vary.
3:1 pitch hole patterns with three holes per inch or 2:1 pitch hole patterns with two holes per inch are used depending on the size of the book. 3:1 hole patterns are good for books that are smaller in size with a 9/16″ in diameter. On the other hand, 2:1 is preferred for thicker books along with a stronger wire.