Airbrush

I can't answer your question but if you go to the Painting section of the Forums, someone there will be glad to help you.  

Jim  

I'll second Fox, try the Painting forum.

You might want to fix your tag, too, it currently reads "aiebrush"

Welcome!

The answer, of course, is "it depends." Paint viscosity, air pressure, airbrush design and even air temperature and humidity all play a factor. Nothing beats going out and playing with the airbrush and your paints.

I suggest you "problem solve." How is your airbrush misbehaving? That will give us a better idea of what to recommend to try and solve the problem.

A quick answer is:

For very sharply defined freehand borders, like camoflague, a fine needle/nozzle will allow close distance spraying with little overspray.

A medium set will produce a much softer border, with noticeable overspray dotting from larger paint droplets. This is useful for spraying where you have areas not to be painted masked, no concerns about over spray. 

A large set I consider more useful for wide area coverage, like a primer, solid color or base coat.

I strongly recommend a look at "Don's Airbrush" website, it's a very well organized and detailed introduction to most everything about airbrushing, very well worth the time investment to gain more knowledge and insight. Guaranteed you'll learn lot's of useful information.

Patrick 

Please refer all questions to proper forum threads! This thread is for introductions, not model related questions.