Sherill Mudtools Mudsponges are always made in the USA. They are compressed pop up sponges made environmentally friendly material that is incredibly durable. They are excellent for shaping, finishing work, final detail and clean-up of surfaces and won't pull out grog or other materials in the clay body. Natural sponges have been used for years. However, the quality of natural sponges can be unpredictable and there is the issue of environmental pressure on the little guys. Our sponges are compressed for economy of space and for the fun of watching them expand when introduced to water.