The XF brand is known for their balls of darning thread. It is an old brand from Lille which, like many others, distributed their threads under different names, the best known being “Au Franc d’Or” and “Au Bon Lorrain”. XF was acquired by Etablissements Vrau in the 1980’s. Along with Fil Au Chinois, Laine Saint-Pierre and Fil Au Conscrit, this brand was taken over by Ets. Toulemonde when they bought Vrau in 2007. The XF knitting and crochet cotton is available in four thicknesses, in white and ecru. It can also be used for embroidery and hardanger.