This spray wax forms a layer over the snow to give support and retard melting. Impression evidence found in snow or ice presents a unique set of difficulties for recovery. Due to the fact that most gypsum-based casting materials generate heat during the curing process, it is necessary to provide an insulating medium. Spray Snow Impression Wax into the impression to prepare the surface for casting. This locks the impression detail to avoid melting when the casting medium is applied. It is supplied in a 15 oz. (425g) aerosol can.