Armour Etch is a fast acting specially formulated glass etching compound that lets you create permanently etched designs on windows, mirrors and household glassware. Create your own custom glass etching stencil or use a pre made stencil like Rub N Etch, Over N Over or Peel N Etch. This unique glass etching system allows anyone to personalize and decorate glass or mirrors in minutes with no previous experience. Not intended for use by children. Will NOT etch Pyrex or plastices. NOT recommended for etching large solid areas of glass.Not recommended for cleaning glass lenses.