Water-soluble homo- and/or copolymers containing alkali metal and/or alkaline earth metal carboxylate groups and based on acrylic or methacrylic derivatives, and corresponding water-soluble homo- and/or copolymers containing carboxyl groups and homo- and/or copolymers containing ammonium carboxylate groups are provided, which homo- and/or copolymers possess excellent suitability for increasing the viscosity of aqueous systems, in particular of print pastes for textile treatment.