Internal Mix

• Airbrushes that mix the paint and air flow inside the head of the airbrush are referred to as internal mix airbrushes. Internal mix airbrushes offer a fine spray pattern compared to external mix airbrushes and are often used by professionals or those with more airbrushing experience. Because the paint mixes inside the airbrush, internal mix airbrushes are slightly more difficult to clean than their external mix counterpart.
  
  

External Mix

• External mix airbrushes allow the paint and air to mix outside of the airbrush at the tip of the needle where the paint is released. These airbrushes have a knob that controls the amount of paint released at one time and has a larger spray pattern than internal mix airbrushes. Maintenance on external mix airbrushes is fairly easy because the paint mixes outside the airbrush, so no moving parts need to be cleaned. This type of airbrush is a good choice for both beginning and experienced airbrush artists.
  
  

Single Action

• Single-action airbrushes have triggers that only control the amount of air that flows from the airbrush. You cannot adjust the air flow, and the amount of paint released must be controlled manually before pressing the trigger. Internal mix airbrushes have a needle adjustment screw to control the amount of paint released, and external mix airbrushes have a fluid cap that controls the amount of paint released on single-action airbrushes.
  
  

Double Action

• Double-action airbrushes, also referred to as dual-action airbrushes, have a more sophisticated trigger mechanism than single-action airbrushes. Artists push the trigger down to control the air flow and pull the trigger back to control the amount of paint released. Double-action airbrushes can create finer lines and give artists greater control to create interesting effects and details. Double-action airbrushes are usually the choice of professionals or experienced airbrush artists.
  
  

Siphon Feed

• Airbrushes that use side-feed or bottom-feed cups, meaning the cup holding the paint is attached to the side or bottom of the airbrush, are considered siphon-feed airbrushes. Air pressure sucks the paint through a tube to mix with the air flow from the airbrush. These types of airbrushes typically have removable cups, making it easy to clean and quickly change colors.
  
  

Gravity Feed

• Gravity-feed airbrushes have a paint cup mounted on the top of the airbrush. Less air pressure is needed to pull the paint in to mix with the air because gravity plays a part in moving the paint. The paint cup usually is permanently attached to gravity-feed airbrushes, so cleaning this type of airbrush is more difficult and changing colors takes more time. Some airbrush artists also dislike the location of gravity-feed cups because they obstruct their view when working on detailed areas of a painting.