Brush on Block translucent sunscreen powder refill. Brush on Block is a natural mineral powder sunscreen that offers broad-spectrum SPF 30 sun protection like more traditional forms of sunscreen but without the mess and grease. It was created to be an all-natural, non-irritating, easy-to-use alternative to thick and goopy sunscreen creams and lotions. Wear your Brush On Block alone or over your makeup, without having to worry about greasy residue.