I have used it over two brands of latex; Behr (Home Depot) and American Tradition (Lowe's). I have weathered the paint by lightly wet sanding. I have also used Testor's acrylic paints and artist chalk for weathering with no problems. The only prep work I do is wipe the surfaces down with a tack cloth before spraying. I use distilled water for thinning and I also use the additive recommended by Nelson Hobby.