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. You will get 1 hour and 30 minutes of techniques and principles of airbrushing that will apply to all types of airbrush art. The video features Air Brush Action's Teacher of the Year for 1995, Debbie Eastlack. Paasche a name brand in airbrushes and airbrush accessories offers up an exceptional video titled PAASCHE Airbrushing with the VL. If you do create your own stencils for airbrushing your automobile do not use paper to create your stencils. 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. By washing the material you will remove any loose fibers. Also washing the material will take care of any shrinking prior to placing your airbrush art design on to the material. So make sure that you have washed and fully dried your material before you begin. Leather needs to be wiped down with rubbing alcohol prior to doing any airbrushing. It may take awhile but with the limitless supply of images and artwork on the internet it is sure to keep you supplied with some inspiration. Sometimes you just need to step back and take a breather to get your inspiration back. If you find that you are not getting inspiration no matter where you are looking then it is definitely time you stepped away from the airbrush art for awhile. Should these parts become dented or damaged in anyway you should replace them immediately. Damage to the air cap and head assembly will effect the performance of your airbrush. Thus like the needle you will be unable to create desirable airbrush art. Both the needle, air cap and head assembly can be purchased at almost any craft or hobby shop that sells airbrushes and airbrush parts.