Sanding block using a spinning lathe, are able to spread the pressure of the sandpaper over a larger surface area allowing the paper to remove all the grains with the same pressure and depth. Using a sanding block achieves the same function. The trick is to remove as little as necessary. Sanding block by hand will remove the softer grains at a faster rate than the harder grains leaving a bumpy surface. We have 4 sizes of sanding block: