The Natural Sea sponge is a 100% biodegradable, environmentally friendly. Sea sponges are known for their excellent absorption, soft texture and durability. Native to the waters surrounding Florida, natural sponges have been used for hundreds of purposes for over thousand years. As these are natural products, the size is not uniform. Natural Sea Sponges for Artists - 4 Pack: Great for Painting, Decorating, Texturing. The unbleached sea sponge is a special painting tool. The sea sponge's natural irregular surface help make unique texture on walls. Great for home decorating DIY projects.