Doubling is a textile industry term synonymous with combining. It can be used for various processes during spinning. During the carding stage, several sources of roving are doubled together and drawn, to remove variations in thickness. After spinning, yarn is doubled for many reasons. Yarn may be doubled to produce warp for weaving, to make cotton for lace, crochet and knitting.[1] It is used for embroidery threads and sewing threads, for example: sewing thread is usually 6-cable thread. Two threads of spun 60s cotton are twisted together, and three of these double threads are twisted into a cable, of what is now 5s yarn. This is mercerised, gassed (AKA flamed) and wound onto a bobbin.[2]