Sanding Sealer is basically our Lite-Coat low-shrink butyrate dope with special light weight, easy-to-sand fillers added that make it the perfect surface primer for a dope finish. Two coats of Sanding Sealer, put on after your initial two coats of clear dope, then sanded thoroughly when dry, will provide an ultra-smooth base for the color dope. Sanding Sealer is completely compatible with all other Sig butyrate dope products.