Internal Mix

An internal mix airbrush introduces paint directly into the middle of the air stream.

This is contrary to the popular theory that paint and air mix inside the nozzle’s tip.   Airbrush construction doesn’t allow air and paint to mix inside the tip.  If air and paint DO mix inside the tip you’re in the middle of a troubleshooting problem.

The Good

• soft, very fine atomization
  There’s more opportunity for the paint to get blown apart by all the energy in the flowing air before the paint makes it out of the air stream.
• even, circular pattern
  It all comes down the way the paint is broken up.  Introduce the paint into the middle of the air stream and you’ll get the larger droplets in the middle of the spray pattern and the finer droplets at the edge of the spray pattern.
• allows the possibility of incredible detail
  Paint leaving the nozzle tip follows a long, pointy needle to it’s ultimate destination on the surface you’re spraying.  That finely tapered needle allows for incredible details that spray guns and external mix airbrushes can’t compete with.

The Bad

• requires thin paint with finely ground up pigments
  The gap between the needle and nozzle only allows smaller, finely ground pigments and less viscous paint through.
• more prone to problems than external mix airbrushesClogging, paint mixing headaches, tip-dry, etc., etc.

The Guru’s Opinion

Internal mix is all the fashion.  This is because the Good completely overpowers the Bad for most people in most industries.  It’s controllable and consistent, even if more prone to problems.