Sheaths or cassettes, also called storage cassettes, are used to keep a book or various booklets together.
The sheaths can be produced in various types of materials. For a more luxurious version of the sheath, it can be produced in hardboard.
For a more simple version of the sheath, it can be produced in corrugated cardboard (usually size ‘E’).
A less rigid version, for smaller sheaths, can be made in flat cardboard up to approx. 400gr.