Armstrong runs a number of different stain tests - we'll start with ASTMF925. Which is actually the ASTM test method for evaluating the chemical resistance of resilient flooring products. That specification, excuse me, that test method is written into all flooring specifications, and looks at a suggested list of reagents. Things like dilute acids, like hydrochloric acid, sulfuric acid, dilute bases, like sodium hydroxide, ammonia. Also look at some other common chemicals or reagents, like isopropyl alcohol, gasoline, kerosene, disinfectant cleaners, mineral oil, and so on and so forth. The way that test works is the reagents are applied to the surface of the flooring, they're covered with a watch glass, so the agents can evaporate. They are left on there for one hour. After which, the sample is then cleaned off and it will be evaluated very closely for any surface dulling, any discoloration of the surface, or any other form of attack, like swelling, or softening of the wear layer.