Colorless, low-odor drying penetrating primer fixative based on acrylic hydrosol, with particularly good penetrating power for the consolidation of mineral substrates as well as for the leveling of strongly or irregularly absorbent substrates. The following substrates are suitable: plasters from mortar groups P II, P III and P IV, concrete/fibrocement boards, plasterboards and plasterboard boards, sand-lime bricks, bricks, concrete and cellular concrete as well as old, slightly chalky but solid paints.