interleaving
OAB Definition
thin sheets of paper or other archival material laid between pages of a book to facilitate note taking or to prevent wear or ink offset. May be tipped in (link) or loose. Notetaking pages are sometimes bound in.
In book arts, the term might reference the interaction between pages of separate textblocks which have been bound as a single structure to allow integrated overlap. In such bindings, pages may lay across each other in the order chosen by the artist or by the last reader of the book.