Aqueous formulations of copolymer latices and polyisocyanate dispersions, containingA) from 5 to 40% by weight of one or more synthetic resins of(a) from 0.1 to 20 parts by weight of one or more monoolefinically unsaturated monomers which carry one or more groups which are reactive with isocyanates and(b) from 80 to 99.9 parts by weight of one or more mono- or diolefinically unsaturated monomers which are copolymerizable with (a) and have no acidic hydrogen atoms,B) from 0.5 to 5% by weight of one or more finely divided, stabilized polyisocyanates,C) effective amounts of dispersants andD) from 5 to 40% by weight of one or more finely divided fillers,are used as coating materials for woven and nonwoven substrates.