Cling On B12 and B10 Block brushes are ideal for applying poly, stain, varnish, color washes, and painting walls. Available in two sizes, the bigger the better! Maybe the B12 is a bit too heavy for you, then go for the B10 Cling on brush instead. Painting table tops a lot? Having a hard time getting it "brushstroke-free"? Use a Block Brush!