Rustins Sanding Sealer Base: Pure shellac & alcohol Seals wood before waxing Seals wood dye to prevent bleeding Coverage (Sq Mt): 13-15 sq metres/litre Container Size: 500ml Rustins 500ml Sanding Sealer | R690043Manufactured from Pure Shellac and alcohol with a special additive included to facilitate sanding when dry. It is also used to seal wood before waxing and to seal wood dyes to prevent bleeding.