Highly effective for concealing and blocking out difficult stains such as rusted metal, rust staining and tannins from hard woods such as oak, mahogany etc. Will also help with water stains on plaster walls and ceilings from leaking gutters, cisterns, roofs etc. and many other “difficult to get rid of” stains. Please Note:- It will not block oily/tarry stains such as asphalt or those from coal fires. Coverage approx 10m2/l per coat. Needs 2 coats. White sample pot available.