M.Coiny was the third generation of goldsmiths of the same name. He became master in 1755, sponsored by his father, a goldsmith in Versailles. His address was on the point Notre-Dame in Paris, where he remained until 1782-83, when he moved to the rue de l’Arbre Sec. Both his brothers, Joseph-Urbain and Jacques-Toussaint, were jewellers or goldsmiths. He was appointed “bijoutier ordinaire des Princes” in 1767, and a warden (garde) of the guild in 1771-72. He may have had a business connection with Jean-Baptiste Beckers (fl.1753-93) since a box by Coiny in the Metropolitan Museum of Art is signed on the bezel “Beckers à Paris”.