ouvreur

opener; forerunner; usher

From ouvrir + -eur.

a worker in papermaking, charged with drawing out the paste from the vat and spreading it evenly to make a sheet; a worker in glassmaking; a worker who fashions textile materials and prepares them for weaving

From ouvrer + -eur (found in Old French as ovrëor, ovreur, ouvreor), possibly corresponding to Latin operātōrem, and therefore a doublet of the borrowing opérateur.