I just get these at Rockler. I have about 5 for different grits and then I can purchase any type paper I need. From each sandpaper sheet you get 4 pieces for the hand sander. I've used this same sander for over 50 years and it has always worked fine. https://www.rockler.com/rubber-sanding-block


~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end