For a post bound book, the collated text block is drilled or punched to allow for binding along the spine. The term "Chicago Screw" is a brand name, currently being used as the common identifier for this type of binding. Post binding can be done as a single pivot point, by pairs, trios (standard for an 8.5x11" book) or other choices.

While the spine is tight and doesn't allow for as much wear as ring bound books, a post bound book will not lay open on it's own. Books that utilize a portfolio or are bound with string, Chicago screws, etc. generally do not lay flat.

This option is ideal for binding for business reports, directories, etc. - all dynamic publications where supplemental or updated pages may be introduced occasionally.  While ease and economy (especially for short run) may make this binding stand out, the fact that the paper involved has been hole punched will reduce the lifespan of the item due to use stress on the holes.  Of the soft bindings that compromise page longevity by putting holes in it, post binding holds up best to usage.  For long-term preservation and usage goals, different soft binding methods are suggested.

Standard types of soft bindings include:

• perfect binding

• traditional tape and staple binding

• plastic or wire comb binding

• plastic or wire coil (spiral) binding

• 3-ring binding

• wire saddle stitch binding

• post/Chicago Screw