Abstract: A composition for optimally removing or etching metallic alloys from chemically compatible substrates with minimal damage to the substrate. The preferred composition is Ammonium Fluoride, Hydrofluoric Acid, Nitric Acid, Phosphoric Acid and Water in a specified range of quantities used to selectively remove an Aluminum and Silicon Alloy and Titanium film from a chemically compatible substrate. The composition is placed in contact with Stainless Steel, Silicon, or other organic or metallic substrates to remove, etch, or pattern homogenous or layered Aluminum, Silicon, Titanium and Copper Alloys from the substrate with minimal etching to the underlying substrate.