The purpose of this opening is so that you can adjust the needle without removing the handle in a single action airbrush. Most experienced airbrush artists will actually take their handle off so that they can deal with clogging issues without delay. So the choice is yours as to whether or not you want the handle on or off of your airbrush while you are creating airbrush art. Preferably get an air compressor that will adjust between 10-18 psi if you do not go with the Iwata Silver Jet. To do airbrush art on nails you will need nail art stencils or nail art masks. 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. Professional Airbrush Techniques by Vince Goodeve will teach you some pretty intricate designs. This book will help you learn how to prepare metal surfaces so that you can begin to learn or advance with airbrush art on motorcycles and cars. While the book will teach you some intricate designs do not worry though cause the book, also has some simple projects that you can start with when working with airbrushing motorcycles and cars. There are a few ways that you can heat set your airbrush art onto the t-shirts so that it lasts. One way is all the design to fully dry then place a cloth over it and iron the shirt with the cloth between the t-shirt and the iron. Always keep the iron moving though so that you do not burn the material. The kit runs around $544 where as individually purchased these items would cost you around $639. For those of you who have experience in airbrush art tattoos and want a kit that will allow you to open up your own business doing airbrush art tattoos professionally, Airbrush Bodyart has you covered. They offer the Airbrush Volume Parlor 2000 kit. With airbrushed tattoos you can get rid of it with baby oil or just wait about 7 days and then it is gone. No need to go and get an even bigger tattoo to cover up the offending one or go through the hassle of laser surgery. To do airbrush art in the form of tattoos you will need certain products. First off you will need an airbrush gun, 10' Hoses braded hose, stencils, glass airbrush bottles and an air manifold.