Just had a nightmare time with Dulux "once" and matt paint. Patchy, despite repeated coats, and as a last resort brought in a professional to try a coat, the finish was just the same. The "once" paint was put over a suitable wallpaper and the ordinary one on matt painted walls. When I complained to the retailer he offered a refund without question, I suspect he has had other complaints previously, he did not even suggest trying to call the Dulux customer service on this issue. On reading your previous threads I would advise all to give this paint a big body swerve.