I only coat up and down, along the 51" dimension of the 51x97" piece of coroplast upon which I tape up my prints for coating. I have permanent, numbered marks at the top and bottom of the coroplast exactly 4" apart. And my spray gun fan is set very close to 8" wide. One coat 1, I go from mark to mark. On coat 2, I go to and from positions 1/3 of the way between marks. On coat 3, the path is between positions 2/3 of the way between marks. I also use a metronome for timing, and I weight the gun at the beginning and end of each coat to verify the amount of paint applied. And when I clean the gun at the end I spend a minute adjusting the spray pattern to perfection for the next use using the cleaning water. I get absolutely, positively zero visible mottling, patterning, or unevenness in the coatings. That's because I'm the next best thing to an industrial robot. But if you're just kind of winging it, it will show. You've got to get coating down a totally controlled and defined routine, or you will lose a lot of canvas. Haven't lost a canvas or got a mediocre coating in a very long time.
