The basics Kett Hydro Proof-RubyTone-30ml created exclusively for airbrush use. The benefits This alcohol-based, water-proof foundation is available in 5 ruby tones: 1,3,5,7 and 9. The uses Smudge-proof, non-transferable, this product stays put until removed and is an industry favorite for everything from tattoo coverage to high-endurance action scenes. Do not use in non-professional low pressure systems. The bottom line This unique product is extremely durable and should have it's own designated airbrush.