WHY DOES MY FLOOD FILL HAVE ERRORS?!
Flood fill was a game changing node, it’s hard to imagine Substance Designer without it these days. In order to work properly, Flood Fill needs shapes to be a binary mask with a single border. If your shapes are too complex and have internal details you will notice errors in your flood fill nodes. You can fix this by using an edge Detect node on your mask. Adjust the edge Width slider to fill in any internal details until the errors disappear. Now multiply your original mask back over the inflated flood fill shapes.