This is from the library of congress - I have used this with various heavy papers etc. Experiment!
The Corrugated Clamshell Box is constructed of one piece of acid-free corrugated board which is measured, cut, scored and folded to form a drop-spine style box which fits the book precisely. This can be made to hold books over 1 " thick, and it works very well for extra large and heavy books. Rare and fragile books need only be handled during the measuring to find length, width and thickness. The book is then set aside and the box dimensions are calculated. The box has no flaps or ties so it is convenient for our curators and reading room assistants to open and reclose while searching for titles in the stacks.
Painting pots on a Saturday evening.
22 hours ago