The Mudsponge White Finishing is made with a tight-cell material and is less absorbent than the Mudsponge Blue Workhorse. It is excellent for finishing work, final detail and clean-up of surfaces and won’t pull out grog or other materials in the clay body. Think of it like a chamois sponge. Natural sponges have been used for years. However, the quality of natural sponges can be unpredictable and there are some issues of environmental pressure on the little guys. Our sponges are made of an environmentally friendly material that is incredibly durable. Net wt. is .015 lbs.