5 Tips for Using an Airbrush

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Guest Author: Sarah Abernathy


-Does your shop have an airbrush laying around, begging to be dusted off?
– Do you have an upcoming project that requires precision and clarity beyond the capabilities of fitches?
– Just looking for a fun new hobby? Don’t fear the airbrush!

With a little practice, you can produce wonderful detail and depth, in a short amount of time!

Before we get to our 5 tips, we must first must choose our weapon!

There are many models and brands on the market, but most will fall under one of two categories: single-action or double-action (or how the trigger works).

Single-action airbrush:

The trigger only moves up and down, which opens up the air flow, pushing paint forward at the same time. These airbrushes are useful for larger area coverage in hobby, craft, stencil, and mural applications.With a very careful finger, you can get a slight variety of air pressure this way, but I would recommend against depending on that for your air control; that should come from the air compressor and, if you have one, the airflow adjustment valve on your coupler. In short, the single-action airbrush trigger lets you release paint or not release paint. To adjust how much paint is being released, you must adjust the cone-shaped tip of the gun, or change the nozzle, which widens or narrows the space around the needle within. This allows more or less paint to flow through when the air pushes it out, but you’ll have to stop in the middle of your paint job to do it.

Double-action airbrush:

The trigger moves up and down, as well as forward and backward. The trigger starts in a forward position. Pushing down on it starts the air flow, and as you pull the trigger backward, the needle inside the cone tip also pulls backward, allowing more and more paint to release, for a more instant control of the flow.

Double-action airbrushes are praised for creating subtle, intricate effects that can’t quite be reached with a single-action. However, the sensitivity of the trigger takes a lot of practice to perfect, which might make single-actions better for beginners.

After you pick your action style, you need to pick the feed  (or how the paint gets in the gun)

Siphon/Bottom feed
Siphon feed airbrushes suck the paint up into the airbrush. These airbrushes are sometimes easier to hold steady since the bottle can aid in gripping your airbrush well for maximum control (two handed grip). They are also great if you want to lay down the same color to a larger area since you have a larger capacity to hold paint. Another benefit is that it can be much easier to switch colors by simply removing the paint bottle, running your brush clean and attaching the new bottle.

Gravity/Top feed
Gravity feed airbrushes allow gravity to help get the paint where it needs to go. These airbrushes have a small cup on the top or side which can be filled with paint. These airbrushes tend to have a more limited liquid capacity and need to be cleaned thoroughly after each color change and use. The upside to gravity feed airbrushes is that they tend to be more balanced and as such are often better suited for fine details.

Pasche Model H – Single action, bottom feed.

 

There are many differences between models and brands that you will have to consider if you’re buying a new unit, or that you will have to practice with if you already own one and just haven’t used it before.  The following tips are based on my experience with a Paasche model H airbrush, which is a single-action, bottom feed airbrush.

5 Airbrush Tips

1. PAINT PREP

Use thin paint, and strain it well with a very tight-weave mesh, like the kind 5-gallon strainer bags are made of. I suggest using supersaturated paint thinned at least 3:2 water:paint. If your paint is too viscous, or if it has any chunks in it, it will clog the airbrush.
Mix 2 or 3 values of paint, using the lightest shade to build up your overall contouring, and using the darkest shade to beef up details near the end. If you jump into your details without a good structure underneath, it will be difficult to work back and build up your values. I recommend starting with a white background and a dark neutral paint, then adding color when you’re comfortable with the process.

2. SURFACE PREP

You will want to paint “up” on a smooth surface. This can be a flat stood up with jacks, a paint frame, or just some extra wall space, as long as your surface is flat. I am used to painting on muslin stretched over bogus paper, which works well because it absorbs moisture more quickly than wood. Primed wood may be too slick, resisting your runny paint and causing drips. Prime your surface, then sand it with a fine grit sandpaper and dust it off. Spray likes to settle on all those little fuzzies sticking up from your surface, giving you an undesirable dimpled texture, but sanding will minimize that issue.

3. IMAGE PREP

If you are producing an image that needs to be picture-perfect (a portrait or other recognizable icon, for example), I recommend projecting your image and tracing. Find the highest quality image possible, especially if you’re using an old-school overhead projector. Draw VERY lightly with a sharp pencil, only hitting the most important moments. If you’re not sure what counts as “most important”, focus on the hardest edges and avoid marking soft tone shifts.
In some cases, masking off bright highlights can be handy. However, relying too much on this can get tricky. Tape creates a hard line, which is not always desirable. I would only recommend taping for highlights that are sharp on all sides and are purely white – for example, I almost always tape off the white reflection in a person’s eyes. If you’re really worried about overspray and you need an area to stay light, consider fluffing up some cotton balls and sticking them to the surface with a little tape. This is a handy technique when painting clouds or other soft, fluffy things. The absence of a hard edge creates a softer effect, but you should still fuss with the edge every so often to break up the profile you’ve made. (If you’ve ever painted a cloud drop with kitty litter or sawdust masking, this is a similar idea.)

4. TOOL PREP

Set up a scrap piece of fabric to get familiar with your gun. Start your compressor with 60 psi and adjust to taste. Practice your aim – in pencil, draw some lines and try to follow them with paint. Make other challenges for yourself, like making straight rows and columns of identical dots. Stick on a strip of tape, dust some paint over the surface from a distance, and pull the tape off, just to see how dark a thin pass of paint is. This experimental step is also critical for troubleshooting – you don’t want your gun sputtering or leaking when you’re working on your precious final project. If paint is sputtering, it may be too thick or not strained enough. If no paint is coming out at all, it again may be clogged, or you need to increase your psi.

Sometimes all you have to do is take the thing apart, give everything a quick rinse and scrub, and put it back together, without actually looking for the problem.
One of the most desirable effects from an airbrush is smooth, razor-sharp lines, used to create wrinkles, eyelashes, etcetera. This will take some fiddling and experimenting to perfect. I like to decrease my paint output to a very light flow, get close to the surface, and move quickly. I only press the trigger down once my hand is already in motion. This is similar to an “airplane landing” with a brush on a bamboo; to avoid hard-edged start and stop points, you lightly touch the brush down as the bamboo is in motion, creating a soft fade at the start of your stroke. The same principle applies in airbrushing. Another method for this effect is to hold the airbrush parallel to the surface as you spray, eliminating the chance of a hard start.

Along with tape and cotton, there are other options for masking off areas you’d like to keep light. Shields are flat tools used a bit like stencils, but more mobile. You can cut them out of stiff, absorbent paper and hold them in your non-dominant hand to block off portions of your image. (Take care not to use glossy poster paper, as your thin paint will immediately run off it and potentially drip onto your surface.) Shields are handy in creating sharp edges, keeping light fields light, and getting dark paint into tight spaces without creating overspray. However, relying too much on shields can be dangerous. If your aim is off, shields can cause ugly overspray marks. If you accidentally touch a wet shield to your surface, you’ll get blotches. If you need a thin dark line that is light on both sides, put the shield down, because you should freehand it. However, if you have a broad field of dark and a broad field of light with a hard line between them, a shield can be your best friend, allowing you to fill the dark field without spending ages crafting that hard line with a tight paint spray.

5. SELF PREP

Have patience. Airbrushing allows you to cover a surface with paint fairly quickly, so it’s easy to rush your process. Personally, I find myself delving into details before building up overall values first. This makes it hard to gauge contrast, and I will end up with dark details and not enough subtlety in the more open areas. My recommendation is to force yourself to keep your hand a certain distance from the surface until you’ve built up your shapes. It’s also helpful to step away from your project every 20-30 minutes, get a drink of water, and come back to it with fresh eyes. One harsh truth to keep in mind: in airbrushing, it is often easier to start over than it is to fight to overcome a mistake. If you have a drip or blotch in the middle of a soft ombre, if you got something wrong in the drawing stage and now someone’s mouth is at an odd angle, if a line that was supposed to be smooth and light has turned out bumpy and dark: consider starting over.

I hope this blog post can serve as a toolkit to anyone interested in picking up an airbrush. Have fun with it, and please share any tips or tricks you’ve picked up in the comments, or in the Guild Forum!


Sarah Abernathy is a graduate from Cobalt Studios and is currently the drop painter for the Asolo Repertory Theater in Sarasota, FL. Sarah will spend her summer in Sacramento, CA, charging for Music Circus. She is an amateur airbrush portrait hobbyist. See more of her work here.
This blog post was written with assistance from Shannon Komlofske, a fellow Cobalt graduate who now charges at Cobalt Studios.

Sarah Abernathy

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