It is a hard sponge used to polish nails. How to use the Beauty Time nail polish sponge. It is used only on dry and clean nails. The sponge has two sides for use... the black side to give a light peeling to the nails and helps remove skin and dead cells from the nails. As for the colored side, it gives shine and a beautiful touch to the nails. It is used with a regular movement on the nails in two steps... the first with the black side and the second step using the colored side of the sponge. It is used according to desire from the soft or rough side