A powdery composition, in particular for coating metal substrates, comprises approximately 70% to approximately 80% of a polyester mixture, relative to the total weight of the composition. Relative to the weight of the polyester mixture, the polyester mixture comprises approximately 57% to approximately 58% of a first copolyester, approximately 35% to approximately 36% of a second copolyester, and approximately 7% of a third copolyester.