Zinsser Cover Stain: - is a high performance oil based primer sealer/stain killer and bond coat. It combines fast-dry convinience with outstanding adhesion and stain killing power. Cover stain can be used on interior and exterior walls, doors, windows and any surface were a fast drying high adhesion primer is required. It can also be used for killing stains such as ink, crayon nicotine, smoke stains & water stains.. Zinsser are moving the production of there products from the USA to a new factory in the UK, this means Zinsser will now be producing there products in european sizes e.g.10 litre, 5 litre, 1 litres and 500ml This will be a gradual process which should be complete within the next few months-as the US sizes are depleated, they will be discontinued and permanently replaced by the UK sizes.