Much of his furniture was produced before Parisian guild regulations required ébénistes to stamp their production, and pieces intended for the royal Garde-Meuble were exempt from such regulations;[2] however, the minutely-detailed inventory descriptions of the Garde-Meuble de la Couronne and inventory numbers stencilled on surviving furniture have enabled scholars to identify a number of pieces from Joubert's workshop.
Francis Watson suggested that Joubert's marriage to a relative of Pierre II Migeon, a favoured cabinet-maker of Mme de Pompadour, may have brought him to her attention and likely through her to court commissions.
[3] For the Château de Choisy he produced, with the engineer Guérin, the famous table volante that rose through the floor for private suppers.
In the decade following 1763 he supplied 2200 pieces of furniture to the court; under the pressure of such a volume of commissions, he was obliged to subcontract even some important pieces of furniture: the roll-top desk he delivered to the comtesse de Provence, 30 December 1773, (Museu Calouste Gulbenkian, Lisbon) was actually made by Jean Henri Riesener,[4] who would succeed him as ébéniste du roi.
[5] Among his most celebrated pieces are the corner cupboards (encoignures) made in 1755 for Louis XV's Cabinet de Médailles at Versailles (Bibliothèque nationale).