Abstract: A method of masking a workpiece at a demarcation zone to facilitate precise spray painting of a workpiece first area on one side of the zone. The method includes providing a mask which has an adhesive backing on one face thereof and a protective liner removably secured to the adhesive backing. The liner is cut or severed so that the resultant sever line has the same conformation therealong as that desired for the demarcation zone. That section of liner associated with the portion of the mask to be affixed to a workpiece second area on the opposite side of the demarcation zone from the workpiece first area is removed from the mask. Thereafter, the mask may be affixed to have the liner sever line precisely aligned with the demarcation zone. Pressure is exerted against the mask at a thin pressure zone coextensive with the demarcation zone to automatically lift that portion of the mask which overlaps the workpiece first portion at and along the demarcation zone to generally form an acute angle therewith.