Abstract: The present invention provides a method for polishing the surface of the transparent substrate layer of a color filter unit comprising a transparent substrate layer, a color filter layer, a protective film layer and a transparent electrode layer, which method comprises attaching, to the surface of the transparent electrode layer, a pressure-sensitive tape consisting of a base film layer and a pressure-sensitive adhesive layer giving substantially no staining to said surface of the transparent electrode layer, formed on one surface of the base film layer, as well as a pressure-sensitive tape used in the method. When the surface of the transparent substrate layer is polished according to the present method, there occurs no breakage of the color filter unit. Further, there occurs no staining of the surface of the transparent electrode layer owing to the adhesion of residual pressure-sensitive adhesive, abrasive, polishing refuse, etc.

Abstract: A method and apparatus for protecting removable markings on an optical lens during grinding thereof to a desired prescription. A mask is placed over the markings prior to application of an adhesive tape, to which a low temperature alloy block is bonded for holding of the lens during grinding. The mask preferably covers only the markings, and is transparent to allow alignment thereof. Preferably the mask is held in place on the lens surface without the use of an adhesive, although a low tack adhesive may be used which does not remove the markings when the mask is peeled away from the lens. A preferred material for the mask is a static cling vinyl.