i shall need to cover a water stain on a ceiling. Such stains always reappear when water based paint is applied directly and so a sealer is required. The person who will be living in the room in question has a very low tolerance of many normal paints and as formulations are liable to change, one can never be sure about what one is buying from a bulk manufacturer. And that is why I bought Earthborn Isolating Primer to go under white Auro Anti Mould topcoat, from the same company Both tins arrived considerably sooner than could be reasonably expected. Both products were painted onto boards, allowed to dry and then the user sat next to the boards for several hours. He experienced very little discomfort and so the products seem safe to use. So everything went well. I shall use this company again whenever possible.