When I was first playing with Lemony Snicket / The Series of Unfortunate Events I had folded down the interior pages and made triangular shaped books to fit the fold. They were single flags but each flag folded down and out itself as well.
Then I got way more inspired with the Series, and went another way. So I had the leftover triangles.
This is a book compiled of those triangles. Tethered together with a ring bought at daiso ages ago, for just this kind of thing.
In a keep cup cardboard container recently gifted to me. The paper with the elephants on it was also a birthday gift maybe 10 years ago.