Detection pastes may be used indoors or outdoors without regard to air circulation. Consideration for rain or high moisture and air content should be addressed before applying pastes to a target object since the dye in the compound is water soluble. Simply squeeze a small amount of paste on the target object in the area that a hand would have to touch, and spread a thin, even coat that will blend with the object‚Äôs color. ALWAYS protect hands with disposable gloves when performing this task. If the target object is touched, transfer will occur and the aqueous dye in the paste will go into solution with perspiration, facial fluids or water with a resulting vivid color appearing. Visible Stain products CANNOT be removed from the surface applied to. VST313 is a Copper natural color and stains Orange.