Picq founded a manufacturing workshop in Paris registering his maker’s mark in 1888. At the time his address was 25 rue des Lehises Saint-Mont. Being a manufacturing workshop he sought to craft jewelry for many different retail firms such as Cartier who he beganing making pieces for in 1900. Picq became a master craftsman in platinum and could work with the metal better than anyone at the time he even started to work in other metals that no one was working with like steel and began blackening it. Picq built many of the outstanding pieces that Cartier sold throught the 1910s including Tiara's and important client bespoke commissions. Picq continued crafting for Cartier until 1918 exclusively then began to work for others including Lacloche and Ostertag simultaneously with Cartier's work. Picq also created pieces for sale under his own name and all having his distinctive mark with the same consistent quality that he produced for Cartier.