They are compressed to save space, will expand with water or exposure to air. Made of round shape foam, soft, absorbent and not easy to deform, help you finish your work easier and faster. Good little tools for art projects. Come up with wallpaper, and great display pieces for your bedroom or living room. These can be used to design small pottery items or to paint a window. For working with clay, crafts, pottery and art paints, also great for household or face painting. Easy to wash and clean. These thick sponges are easy to hold and last long time which still won't feel tired.