The invention relates to a masking layer. The masking layer produced by coating a white-color photosensitive resin composition on a peripheral region of a transparent substrate, developing the white-color photosensitive resin composition to obtain a patterned composition layer, coating a gray-color photosensitive resin composition on the cured composition layer and developing the gray-color photosensitive resin composition, so that the gray-color photosensitive resin composition is cured to obtain the masking layer having an optical density (O.D.) of ≧3.5. The masking layer is adapted for use on a touch panel or a flat panel display device. The masking layer shows a white color appearance when viewed from outside and serves as a white color decoration around the peripheral region of the device. The masking layer further comprises a gray colored sub-layer to mask the electrical circuitry disposed beneath the masking layer.