Two spine sizes (the larger has the capacity to bind several hundred sheets)

Spine capacity Inches Millimeters Sheets of paper 3⁄16" 4 mm 16 1⁄4" 6 mm 25 5⁄16" 8 mm 40 3⁄8" 10 mm 55 7⁄16" 11 mm 70 1⁄2" 12 mm 85 9⁄16" 14 mm 100 5⁄8" 16 mm 125 3⁄4" 20 mm 150 7⁄8" 22 mm 175 1" 25 mm 200 1+1⁄8" 28 mm 250 1+1⁄4" 32 mm 275 1+1⁄2" 38 mm 325 1+3⁄4" 45 mm 375 2" 51 mm 425

Comb binding (sometimes referred to as "cerlox" or "surelox" binding) is one of many ways to bind pages together into a book. This method uses round plastic spines with 19 rings (for US Letter size) or 21 rings (for A4 size) and a hole puncher that makes rectangular holes. Comb binding is sometimes referred to as plastic comb binding or spiral comb binding.

Binding process

To bind a document, the user first punches holes in the paper with a specialized hole punch. Pages must be punched a few at a time with most of these machines. If hard covers are desired, they must be punched as well. In bulk applications, a paper drilling machine may be used.

Then the user chooses a spine size that will match the document. Standard sizes are 4.8 mm (3⁄16 in) (for 16 sheets of 20# paper) up to 51 mm (2 in) (for 425 sheets). Spine lengths are generally 280 mm (11 in) to match the length of letter-size paper.

The rings on the spine open and insert into the holes in the page, then rest against the body of the spine, resulting in a closure that can be opened again for making changes to the book.

• 
  Machine opening the spine
• 
  Pre-punched paper with spine rings through holes
• 
  Rings closed on paper
• 
  Completed book out of machine

Comparison with other punch binds

With this bind, the book lies flat but cannot be opened 360 degrees. For a book that can be opened such that the covers touch, a spine that does not have an obstructive body, such as a coil binding, is a better option.

References

• How To Comb Bind
• About.com Desktop Publishing article