Poundo boards are rubber surfaces that are used for bade protection or shock absorption in leather working. When cutting or punching with leather tools, the tool blades pass through the leather and onto a surface underneath. If this surface is hard, it could damage the blade. If this surface is soft, the blade goes lightly into the material, protecting the blade and the surface underneath.
These rubber boards come in a variety of sizes and are usually black in color. They can also be placed underneath a granite or stone slab when punching or pounding, to help with shock absorption.