This is a premium professional grade modeling clay. A growing number of professionals including sculpture studios, clay art therapists and taxidermists are choosing this clay. This moist water based clay is extremely versatile with plasticity properties similar to many of today's most popular oil based clays. Like any water based clay, this clay needs to be kept moist to prevent hardening, preferably with a spray bottle or a damp towel. Saran wrap is also commonly used to keep clay moist during the sculpting process.