Coptic Binding
Coptic binding or Coptic sewing is a type of thread sewn binding. This method of bookbinding was first employed by early Christians in Egypt, the Copts, and used from as early as the 2nd century AD to the 11th century. The term is also used to describe modern bindings sewn in the same style.
Basically folded sections are section sewn and then glued down the spine. This gives a securely bound book with the stitches visible.
Coptic bound books open very flat which is often desirable for example in instruction books or recipe books.