I was wondering how flexible your notebook covers are, and if they might work inside a homemade traveler's style notebook cover? I have some lovely black faux-leather that I'm considering using for such a purpose, and your little blank notebooks seem like a nice way to divide up my nefarious planning... and possibly my housecleaning schedule, too.
If you are familiar with paper weight measurements, they are 65# cover stock. If not, they are a comfortably thick paper, but still very much “paper” and not stiff. Bends easily, folds if you apply pressure to it.
A bit heftier than an index card.