Erasing pads (also called eraser sponges) are polymer foam pads typically made of white melamine foam and blue urethane foam. The white foam erases marks and scuffs and won't scratch glass, tile, or stainless steel. The blue foam retains water to keep the pad moist. These reusable erasing pads require only water, so there's no need to add detergents or cleaning solutions. They're ideal for removing smudges, ink, and grime from walls, floors, and other hard surfaces. Erasing pads are not recommended for dishes or food preparation surfaces since the pads can shed bits of polymer.