Single action or double action gun for airbrush makeup?
This is one of the most basic questions facing those who approach airbrush makeup for the first time, especially professionals, and one of the most confusing. The reason for the confusion lies in a colossal misunderstanding of the terms themselves, which changed meaning as they started being used by the cosmetic industry. [If you just want the straight answer, please scroll to down to IN CONCLUSION, or keep reading for the whole mystery exposed!]
In "orthodox aerography", that is in traditional technical terms, a single action airbrush is one that dispenses colour by simply pushing down the trigger (or "lever"), hence the term "Single Action". The trigger does not slide back to release more colour, it can only be pushed down, and the colour and the air are dispensed at the same time much like a spray can would. You can already breathe a sigh of relief here, because NO AIRBRUSH COSMETIC COMPANY SELLS THESE. So you would have to go out of your way to find an airbrush like that to add to your kit.
To continue with traditional aerography, a double action airbrush is one where the trigger has to be pushed down to release air first, and then pulled back to release the colour gradually, the further back you pull, the more colour comes out. If you pull the trigger back without pushing down for air first you create a backwash and possibly splatter paint. This kind of airbrush is the most widely available for traditional airbrush painting.
When cosmetic companies started producing kits for commercial distribution, they looked to offer a simplified version of the double action airbrush described above. They wanted consumers to be able to regulate colour flow with the trigger, but they did not want to complicate their lives with having to push down the trigger for air first, and the problems that can arise if you don't. So they started producing (or commissioning their suppliers, in most cases) airbrushes in which air would flow unobstructed from the moment the compressor is turned on, called continuous airflow airbrushes, and where the trigger could be simply pulled back to release colour gradually. They then proceeded to rename this type of airgun "single action airbrush" in their marketing, creating the massive confusion reigning today. All the rants you find on websites like Model Mayhem or Beautylish against "single action airbrushes" are based on this misunderstanding, with a lot of gurus referring to the actual single action as described at the top of this post, rather than the "continuous airflow" conceived later.
Where airbrush beauty makeup is concerned, the only difference between single action (continuous airflow) and double action airbrush is that with a double action you have to push the trigger down to release the air before you pull it back to release the makeup. That's it. That's all. In short: a nuisance, considering that if you forget to do so you run into paint back flow problems, and that the stopping and starting of the air is harder on the small sized, maintenance free compressor that most kits come with.The sudden burst of air is also very annoying for the clients, who are inevitably startled by it and tend to jump back in the chair.
The most common objection that "with a double action airbrush you can feel where the makeup is going to be by releasing the air before dispensing the colour" is moot, because with a "continuous flow" airbrush you can do the same just by pointing the blessed thing before pulling back the trigger.
This is why even pro companies like TEMPTU PRO have now started offering single action (continuous airflow) guns in their professional kits, while KETT Always had the best of both worlds by selling a gun that they call Transformer, that can be switched to "single action" by simply substituting a small valve (included in the box).
If you don't already own an airbrush, a continuous airflow "single action" airbrush is better, easier and more efficient for airbrush makeup in general. A double action requires more practice, although it could be better for body painting if you are looking for special spatter effect that can only be obtained by stopping and starting the air. If your area of interest is SFX rather than beauty makeup the whole thing changes of course, but we will discuss that aspect in a future post. [If you come from the top of this post having skipped the middle part and still have doubts, well... you just may have to read the whole thing after all...]
PRO TIP: THIS FANTASTIC BLOG ARTICLE will explain how to turn your double action airbrush into a "single action, continuous airflow" one with a few simple moves and at zero cost. We tested the method and it definitely works on all Sparmax airguns (Sparmax is the maker of the airguns distributed by Kett, Temptu, Graftobian, Kryolan and Airbase among Others). Please use extreme caution and read the relevant disclaimers.
|Kett's Transformer Airbrush
|TemptuPro's "Single Action" SE50 Airbrush