Based on cellulose ether. Characterized by their broad property profile: low spattering when applied by brush or roller, high water retention capacity, allows lap-free application by brush or roller, no pigment flocculation thus optimum use of color pigments, uniform and high-covering films with outstanding wash and scrub resistance, good storage stability, allows sparing use of preservatives, good thickener effect, allows particularly economical metering. Can be supplemented by combination with suitable synthetic thickeners. Suitable for silicate emulsion paints. Chemically treated to delay their solubility. Makes it easy to incorporate into the coating formulation.