This is an album stand I made for a co-worker. It is solid ash wood (except for the bottom of the box that is plywood).
This is a planing sled to flatten warped boards if you don't have a jointer.
This is a closeup of the planing sled. Shims are placed under the board to keep it from rocking so the planer can create a flat face. The shims are held in place with hot glue which is easy to clean up.
This image shows the sled with a board on it going through the planer to smooth one face. The board will then be removed from the sled, flipped over, and run through again to flatten the opposite face.
This image shows the planed boards ready to cut to size. Notice the face is smooth but the rough edges still need to be removed.