Tech inspector is right. There have been a lot of people inquiring about the same thing. I only have first hand experience with the product that I mentioned,but there are a lot of other products out there,most commercial,so I wouldn't know how you could get them. The most common way to square is to put down a coat of white,solid. Dry,and then come back with the coat of black on top in the pattern that you wish,taping that pattern off of course. By the way, Techinspector is the man!