I was wondering what type of airbrush you are supossed to use when decorating a cake.....I am going to the store today to buy one but they said that dont have one specific for cake decorating.
Thanks

Any airbrush will work. Make sure you get a double action. Double action gives you better control. Some of the best on the market are Badger and Paasche. You want to get a gravity feed not a bottom feed. If you can wait a good airbrush at a good price is the Paasche VSR90 from dixieart.com. It runs $65 shipped, you can get a KopyKake Airmast Plus compressor from bearair.com for $159 plus shipping. They run $300 plus anywhere else.

If you get just any old airbrush, how thin should your color be ?

And can you thin down the paste colors or does it have to be airbrush kind ?

The needle size in the brush determines how thin the colors have to be. A standard airbrush comes with a .30 mm needle for thin liguids and decent detail work. The Paasche comes with 2 needles. The .30 is in the case and a finer needle is in the brush. It is for very thin (cake airbrush colors) and very fine detail. Do not water down the gels. They will not spray well and are very difficult to clean out of the brush.
Something most people do not think about is a standard airbrush is set up to use paint. Paint is a whole lot thicker than airbrush color, even when it is thinned.

Lots of great information.. I was curious as well.

Thanks CigarHerb - I have it on my wish list too and just didn't want to get just any airbrush. I want to get one that is useful and easy to operate. I have never used one...so the less problems the better!