Which form of hair removal requires the hair to be at least ¼ inch long?

Waxing requires the hair to be at least ¼ inch long for optimal results. This length is necessary because the wax needs to grip the hair effectively to remove it from the follicle. If the hair is too short, the wax may not adhere properly, leading to incomplete removal and potentially causing irritation to the skin.

Other methods of hair removal, such as shaving, do not have this length requirement as they cut the hair at the surface level without pulling it from the root. Electrolysis, while effective for permanent hair removal, can treat shorter hairs because it directly targets the follicle with an electrical current. Threading can also work on shorter hair, as it removes hair by trapping it in a twisted thread and pulling it out from the follicle without necessitating a specific length.