The nail art masks are reusable masks that have an adhesive that does not leave any residue on the nails. Of course if you are really creative and very good you can freehand the airbrush art right onto the nails. If not then take the time and invest in nail art stencils and masks. The paint that you will use when doing airbrush art on nails is water based. The bottom feed is where the cup is mounted to the bottom of the airbrush and the paint is brought up via a siphon tube. It is for this reason that the bottom feed is also referred to as a siphon feed. Since the artist can attach the cup to the bottom of the airbrush the colors can be changed quickly by using different cups prefilled with the colors needed. This kit includes a 4 outlet air manifold, 4 single action ABA airbrushes, 12 glass airbrush bottles, 4 air hoses, 10 60ml of airbrush art tattoo inks in white, blue, red, yellow, violet, fuchsia, green, fluorescent green, fluorescent yellow and fluorescent blue and 1 120ml of black airbrush tattoo ink. There is no healing time needed with airbrushed tattoos. The great part is there is no pain involved. Real tattoos come with pain and is one of the reason that some people do not get them. So using airbrush art to create a tattoo gives people the chance to have realistic tattoos without the pain. Real tattoos are permanent and you are stuck with what ever you get. To start with you need to practice with simple techniques until you get the hang of how to do them. Simple techniques will give you a better understanding of the process and allow for you to have a foundation in which to build on. When you first try using an airbrush you need to use a cheap surface that you can just practice with. Solvent based paints should be cleaned with a solvent based cleaner. All water based paints can be cleaned with water or a commercial cleaner designed for airbrushes. Windex is useful when cleaner your airbrush between color changes while using your airbrush. Never soak or leave your airbrush exposed to Windex for any real length of time.