What is the difference between an interface pad and pad saver? When do I need to use them?

A pad saver is the thin black Velcro pad that comes with your sanding system to help prevent damage to your RFBP (red foam backup pad). It should always be used whenever you are using any of SurfPrep’s paper, film, or screen abrasives on your sander. It is not necessary to use it with the padded foam abrasives. Using your pad saver will help prolong the life of tiny nylon hooks on your RFBP. 

Interface pads come in various thicknesses and foam densities. They can be used in conjunction with any of SurfPrep’s abrasives to create a stacking effect to level sand profiled surface areas to compound curves and unique profiles often found on furniture and custom cabinetry.