The material of the poly clay beads is smooth and skin-friendly. It will not be allergic or hurt to the skin. Please keep the beads and other accessories away from water. Plus there is a tiny but sharp scissor and one disc of 33 feet elastic strings that is available for 20 necklaces/60 bracelets/100 pairs of earrings. Each kind of clay disc bead is sealed separately in a plastic bag. Thus, these rubber beads would be mixed up neither in transportation nor in daily use.