I have been using the Auto Air paints for all of my mural work. I use either Sherman Williams or Dupont Chroma Base for my base coats. I know there is a controversy over the Auto Air vs urethanes for graphics and murals. If I want to use urethanes, what do I want to use? I know HOK makes it very easy to use their line for everything. I was wondering what the equivalents in other brand were (i.e. Dupont and PPG etc.)