Bookbinding
Among the experiments of earlier centuries, scrolls were sometimes unrolled horizontally, as a succession of columns. (The Dead Sea Scrolls are a famous example of this format.) This made it possible to fold the scroll as an accordion. The next step was then to cut the folios, sew and glue them at their centers, making it easier to use the papyrus or vellum recto-verso as with a modern book. In traditional bookbinding, these assembled folios trimmed and curved were called "codex" in order to differentiate it from the "case" which we now know as "hard cover". Binding the codex was clearly a different procedure from binding the "case". This terminology, still in use some 50 or 60 years ago, has been nearly abandoned. Some commercial bookbinders may refer to the cover and the inside of the book instead, but a few others, attached to their traditions, still use the terms "codex" and "case".
Read more about this topic: Codex