Desizing is a wet finishing process that removes the sizing agents applied to warp yarns during preparation. Sizing protects the yarn from the heavy mechanical abrasion of the loom, but it leaves the woven fabric stiff and resistant to dyes. Mills use enzymes, hot water, or mild acids to break down the starch or synthetic polymers so the fabric can be dyed, bleached, or printed.
Heard on the job
We need to desize these cotton rolls before they go into the dye bath or the color will come out patchy.