A fiend of ours contacted me about making some book risers. This firend has just moved to a new house that has some built-in bookshelves that are deep and tall, which is nice for hardbacks but inefficient for paperback. My solution is to stack books vertically and sideways.
Not everybody like this solution, though. They like to be able to see at least a portion of all the spines, even though it is less efficient.
To achieve this, though, you need some kind of riser. I know people who use foam blocks, or cardboard inserts, but plywood is way stronger and more durable, so this friend contacted me.
Here they are being painted matte black in the driveway. They are basically just open-bottom boxes. There is an extra support piece in the middle, just to keep them stable. They are made from half-inch plywood, with simple butt joinery, glue, and 23 gauge pins. Two different sizes, one for paperbacks and one for trrade paperbacks. They are clear-coated to keep the black from rubbing off, and felted on the bottom to keep from scratching the shelves. They are not perfect, but since once they are in place it is possible that nobody will ever see them again, that’s probably OK.