Silver Rainbow EcoGlitter: This super sparkly glitter is made from cellulose fibers, and is 100% biodegradable. Add a heavy dose of sparkle to your products without worrying about the environmental impact. This glitter works beautifully in melt and pour soap, scrubs, bath bombs, and nail polish.It can be used for decorating the tops of cold process, but does dissolve if added to the batter. Best on soap that is thick enough to fully suspend the glitter above the batter.