The present invention relates to a pigmented aqueous basecoat material comprising a polyether-based reaction product which is preparable by reaction of (a) at least one compound of the formula (I) X1—Y—X2  (I) in which X1 and X2, independently of one another, are each a functional group which is reactive toward hydroxyl groups, and Y is a divalent aliphatic or araliphatic, carboxy-functional organic radical having a number-average molecular weight of 100 to 1000 g/mol, with (b) at least one polyether of the general structural formula (II) in which R is a C3 to C6 alkylene radical and n is selected accordingly such that the polyether (b) possesses a number-average molecular weight of 200 to 4000 g/mol, where components (a) and (b) are used in the reaction in a molar ratio of 0.7/2.3 to 1.6/1.7 and the resulting reaction product possesses a number-average molecular weight of 500 to 15 000 g/mol and an acid number of 10 to 120 mg KOH/g.