One of the things I like most about Gaming Ballistic's DTRPG bestiaries is the monster reference cards. They're 4x5 inch cards, big enough to be quite visible across a game table, with an illustration of the monster on one side (with a human silhouette for scale) and full monster stats on the back. Players can visualize what they're running into, and the GM doesn't have to keep one more book open on the table to check stats. Very useful. The concern I've always had, though, is that they come in the form of a deck of cards. That's trivially easy to knock over inadvertently or just drop and scatter all over the floor, so I've needed a storage solution. My first instinct was to work up a design for a box and 3d print it. I did, but it just didn't do it for me. I recently realized, though, that 4x5 cards would fit nicely in photo albums (I'll tell you kids about photo albums later) designed for 4x6 pictures. Cheap and easy solution, though ironica...