Abstract: A thin strip of liquid-impermeable polymeric material has a strip of porous material secured to one of its surface to form a flexible sheet. A pressure sensitive adhesive element, which is more adherent to the porous material than to hair, is adhered to the other surface of the porous strip. The pressure sensitive adhesive element is used to attach the flexible sheet firmly, but releaseably, to the hair of the head of a person adjacent to the portion of hair which is to be treated. In using the sheet, a colorist places the first end of the sheet with the adhesive element on the hair and then presses on the liquid-impermeable surface to cause the adhesive element to firmly adhere it in place against the underlying hair. The colorist then weaves an amount of hair over the face of the liquid-impermeable surface, followed by the treatment of that hair with a wet hair treating agent.