Quick little project to organize my jigs. Shelves within shelves, 3/4 OSB is cheap and pretty strong. I didn't put supports midway between as I didn't want to give up any usable space. Not much weight on them and if it sags it won't be much of an issue. Supports easily added later if it really becomes necessary. I gained a whole shelf for stuff and more space is always nice. I used precut 2 x 4 foot precut panels, 4 x & sheets would have been cheaper but they're getting hard to handle by myself.