I made these to give my kitchen cabinets a little more storage space. While I was at it, I also made a couple for my mom’s spice cabinet. The wood is 1/2” poplar. The racks are 4.5” tall and 2.5” deep. The width varies based on the width of the cabinet door. The dowel is 5/16”. On mine, I angled some screws into the door from the top and bottom of each side of the rack. I decided this was dangerous in terms of the screw potentially blowing out on the front side of the door, so on the version for my mom, I glued small cleats on the inside of the racks to use for screwing straight into the back of the door.