Automobiles need lots of paint and this will damage paper stencils rather quickly. So stick with plastic or vinyl material for your stencils. A great cheap plastic to use for stencils is thin plastic folders. These can be picked up cheaply in office supply areas of most stores. When doing airbrush art there are different types of airbrushes that are available. The paint will become permanent when it dries. There are a lot of possibilities with acrylic nail art paint that you can do when creating your airbrush art. Colors can be mixed to create your own unique color for your artwork. When putting airbrush art onto an automotive use acrylic enamels. These are not only cheap but they will not clog up your airbrush like lacquers. If you are doing a stencil for say a dog then you would want to take your time and make sure that the eyes were the same size, the nostrils were cut out shaped the way they should be and so on. If you rush you could end up messing your stencil all up. The stencil is to aid you in creating your airbrush art and is a big part of the art process. While this may seem stupid it will help you to learn how to create designs using your airbrush. Continue to practice with shapes until you are able to perfectly render airbrushed shapes. Once you have the ability to render the shapes, you can move on to rendering shapes in different textures. This means that you should work on creating shapes with thin lines and shapes with thick lines. The less air pressure means that you can use slower movements when airbrushing. 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. The interior of your home is also a place for airbrush art. You can go with a nice mural on your wall to give a room in your home an artsy feeling. Or you can scale it down and just airbrush a border at the tops of the walls. Airbrushed borders look more decorative than glued on paper borders on your walls.