Captain Creative Super Sponges are made of real cellulose sponge material and they are one inch thick. It is best to rinse and wash the sponges before the first use and for every use after that. Each pack will contain a variety of shapes, colors, sizes and quantities with no two packs typically the same. Super Sponges are great for sponge painting, sand and water tables, and bath time. Super Sponges are 1" thick and made of cellulose sponge material perfect for sponge painting and water play. The sponges are not made for children under the age of 3 years old.