Acrylic Stop Out

I have found a product sold under the name of Sax True Flow Tempera Varnish. It is an acrylic styrene co-polymer. This mixed with acrylic floor polish it becomes an excellent stop out and resists with one coat. The proportion is 1 to 1 acrylic floor polish and True Flow Temper Varnish and color with water proof India ink to your satisfaction. I prefer Kohlinoor India Ink because it is pigmented better however any brand will work. To remove the ground use sodium carbonate and hot water. The Sax True Flow Temper Varnish is a styrene co-polymer and is broken down by alkaline solutions like sodium carbonate or ammonia.