Transparent drying concentrate with maximum dilution reserve, for deep priming and solidifying highly or differently absorbent, sanding substrates. Suitable are plasters of mortar group P II and P III, gypsum plasters of mortar group P IV, concrete/fibre cement boards, gypsum construction and gypsum plasterboard, lime sand brick, brick and hard branded brick, concrete and aerated concrete as well as slightly chalking but stable old paints.