In threading, a thin cotton thread specially designed for threading is doubled, then twisted. It is then rolled over areas of unwanted hair, plucking the hair at the follicle level. Unlike tweezing, where single hairs are pulled out one at a time, threading can remove short lines of hair.
Advantages cited for eyebrow threading, as opposed to eyebrow waxing, are that it provides more precise control in shaping eyebrows and is more gentle on the skin. Because several follicles are removed at once, it can be painful, though a Guardian columnist has declared that when done professionally "with a cat's cradle of fine thread" it can be quick and painless.