Armour Etch® Glass Etching Cream. Armour Etch is a fast acting specially formulated glass etching compound that lets you create permanent etched designs on windows, mirrors and household glassware. not suitable for plastic Armour Etching Cream is a special formula that safely and easily removes a fine layer of glass from windows, mirrors and other glass objects to give them an attractive etched appearance. Using contact paper or any craft stencilling paper that has a sticky back you can draw a design, then cut out the portions of the paper that you want to etch. Please take care when using this etching cream, as prolonged contact with skin can cause burns. KEEP OUT OF REACH OF CHILDREN.