Abstract: A powder of a copolymer with polyamide blocks and polyether blocks. The invention concerns a composition comprising a powder of a copolymer with polyamide blocks and polyether blocks, the copolymer being in particle form with a pulverulent filler content of 0 to 10% by mass and the copolymer having a ratio by mass of the polyamide blocks to the polyether blocks of less than or equal to 0.7, the polyamide blocks having a number-average molar mass of less than or equal to 1000 g/mol; and the composition comprising a flow aid at a content of greater than or equal to 0.3% by mass. The invention also concerns the process for producing this composition, the use of the composition for constructing three-dimensional articles, and the three-dimensional articles manufactured from said composition.