Coming from a family of silk merchants, young Grégoire began creating painted velvets at the age of 26. His astonishing technique and extremely detailed works first made him a name in Aix, then in Paris, where he worked under the protectorate of the Count of Angiviller, director of the King's Buildings Administration. Grégoire's unique method involves applying paint directly to the warp before weaving begins. Thus, his portraits are neither printed, as on plain fabric, nor shaped, as would have been the case with the “large print craft”. This innovation allowed Grégoire to achieve the finesse of the line and the subtlety of extraordinary colors. Several of his works are today kept at the Fabric Museum of Lyon, Aix en Provence and Marseille.