The invention relates to a plastic composition, comprising (a) at least one polar thermoplastic polymer; (b) at least one metallic salt of an unsaturated aliphatic fatty acid; (c) at least one polyhydric alcohol, the melting point of which is no more than 80° C. below and no more than 50° C. above the melting point of the polymer (a); and (d) at least one further alcohol that is different from the alcohol (c), and the boiling point of which is no more than 100° C. below and no more than 80° C. above the melting point of the polymer (a).