Airbrushes of all brands, shapes and sizes are defined by two categories above all else: the trigger action and the feed. This is about the latter, as we review the differences between gravity feed and siphon feed.
Gravity and Siphon
Besides the trigger action, the type of feed is one of the most important feature of airbrushes. The feed is, as the name suggests, how to paint gets from the cup to the nozzle, and ultimately, out of the airbrush and on your miniature. Gravity and siphon are the two most common ones, and each come with a solid list of pros and cons.
If you want to get into airbrushing, most starter sets come with multiple airbrushes, usually, at least one gravity and siphon. This means you get to at least try each of them, or alternate depending on the task at hand.
There is also such a thing as side feed, which features some pros and cons of both types. These are far less common, however.
Gravity feed is pretty self explanatory. The paint reservoir is on top of the airbrush, and gravity does the work of letting it through into the nozzle. It is by far the most common and most polyvalent of feed option.
Gravity feeds offer the most control over paint consistency, allowing you to spray with very thin paints or inks with ease. It’s also easier to mix in or switch colors.
The biggest drawback of gravity feed is that it is much more prone to clogging. Because the paint goes straight in the nozzle and all mechanism, if your paint is too thick, you are force feeding it into the nozzle, which is never great.
While siphon feeds are almost always one-sized fits a lot, gravity feed cups come in various sizes. It’s important to check that the size of the cup matches the use you want out of the airbrush. A small one like the Sotar’s won’t be much use for base coats as you will empty it after three models.
Siphon feed, also called suction feed, is the spray gun’s paint delivery method of choice. Your paint is sucked through a straw in the cup and sprayed from the front of the airbrush.
The biggest perk of siphon feed is that it is extremely easy to use. Too thin or too thick, and your paint simply won’t leave the cup. This is also a disadvantage of sorts, as you can’t spray with any paint consistency. You need to stay in the suction’s sweet spot of working consistency.
This is not a big drawback, as that consistency is great for primer and base coats, which is where most suction fed airbrushes and spray guns come into play.
My favorite part of siphons is that the cups are almost all the same, and you can buy extras with lids to save your mixes.