Armour Etch is a fast acting specially formulated glass etching compound that lets you create permanent etched designs on windows, mirrors and household glassware. Create your own custom glass etching stencil or use a pre-cut stencils. This unique glass etching product enables anyone to personalize and decorate glass or mirrors in minutes. -No previous experience required -Not intended for use by children -Will not etch plastics or some Pyrex -Not recommended for etching large areas of glass over one inch by one inch