The purpose of the needle is to control the paint flow. Any damage to your needle can cause very bad paint spray patterns. It is important to keep your needle from getting bend and either straightening the needle or replacing the needle. The air cap and head assembly are on the front of your airbrush and they cover the tip of the needle. Once you are comfortable using the airbrush then you should work on creating shapes with your airbrush. Using a cheap surfaces airbrush circles, triangles, squares and rectangles. 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. Make sure that all the leather has been wiped down and that the alcohol has dried before beginning. When you begin you need to place a base coat of Opaque White first before you begin your actual airbrush design. Wood surfaces should be sanded prior to doing any airbrush art. Take the time to use sand paper and lightly sand the wood down by hand. Airbrush art goes on quickly thus saving lots of time compared to henna as well as airbrush art is waterproof. Unlike henna lots of exposure to water still will not fade your tattoo. Where it would take an artist 6 hours to pain on a large henna design the same artist could airbrush the design on in around 30 minutes. Keeping your equipment in proper working order and clean will save you a lot of money and hassles. Equipment that is not kept clean and properly cared for will break down more often. Also equipment in is not taken care of and cleaned will not produce quality airbrush art. First let's look at how to clean your airbrush. Also the time frames are shortened when the paintings are airbrushed versus hand painted. Family portraits can be airbrushed over hand painted as well to give for a more realistic painting. 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.