Most artists find the using their airbrush without the needle cap gives them more control. Removing the needle cap is fine but should you hit your airbrush against something or drop it you could end up damaging the needle itself. So to take care of your airbrush make sure that when you are not using your airbrush that you replace the needle cap back onto it. Now when it comes to the feed on the airbrush there are three types of feeds that you can choose from. The type of feed you choose will also depend on what you are doing as well as what you are comfortable working with. The gravity feed is a top mount cup that uses gravity to pull the paint down into the airbrush. Airbrush art can be seen in magazines that are designed to teach techniques geared toward airbrushing in a more broad-spectrum. Airbrush art can also be seen in magazines geared toward airbrushing cars or bikes and such. Making for much more precise content toward a more specific niche. Airbrush Technique Magazine is a broad spectrum magazine that is geared to teach techniques of airbrush art no matter what you are airbrushing. A good automotive lacquer will work fine to thin down your automotive paint. Different airbrush art calls for different psi on your compressor. PSI stands for pounds per square inch and for automotive airbrush art you need a compressor that has a psi of 55-65. Iwata is a great name brand to go with and they offer four compressors that will work for airbrushing automotives. Her series teaches about airbrushing flames, murals and masking techniques and motorcycle gas taking airbrushing. Her videos will give you a more visual learning aid than you would get from the detailed directions in her books, so if you learn better from watching then the videos are your best bet when learning from Shanteau. Skin should be cleaned with rubbing alcohol to remove any oils from the skin. The skin's own natural oils will prevent the airbrush paint from successfully sticking to the skin. This will cause the airbrush art tattoo to come off to soon. The use of talc powder after the design has dried will help to keep oil from building back up and thus still ruining the airbrushed tattoo.