Abstract: Size-adjustable wheel rim protective masks for protecting a wheel rim from overspray during application of tire dressing to the surrounding tire. A generally flat, circular disk is provided having a radial gap, such as a slit, so as to be reconfigurable into a plurality of cone-shaped configurations corresponding in size to a wheel rim to be protected. An adjustment locking mechanism is provided for locking the circular disk into a desired cone shaped configuration. The locking mechanism may comprise mateable male and female snaps, a tab and recess system, a hook and loop system, adhesive tape, a belt and buckle system, a ratchet band and clasp system, or other locking mechanisms known in the art. A pair of finger holes or a handle structure facilitates gripping of the protective mask during use. The disk is preferably made from a water and chemical resistant material such as plastic.