Priming Miniatures: Everything You Need to Know
Hey again, friends. If you've just finished assembling your models and you're staring at them thinking "now what," this is your next step. Priming. It's the bridge between assembly and painting, and it's one of those things that seems dead simple until you get it wrong. Then it's a nightmare.
I've sprayed primer in the wrong conditions and ended up with models that looked like they rolled through a sandbox. I've brushed on primer too thick and watched detail disappear under a layer of goo. And I've also nailed it hundreds of times and had models that were an absolute joy to paint because the primer went on clean. The difference comes down to knowing a few things that nobody tells you when you're starting out.
What You'll Need
- Miniatures— Clean, assembled, and ready for paint
- Spray primer— Choose a color appropriate for your scheme
- Respirator mask— Protect lungs from aerosolized paint particles
- Gloves— Prevent fingerprints and keep hands clean
- Clipping sticks or holders— Securely hold models without touching surface
- Tack-it or mounting putty— Attach models to holders for easy handling
- Cardboard box or spray booth— Contain overspray and protect surroundings
- Weather station or thermometer— Monitor temperature and humidity for best results
Why Primer Matters
Let's start with the obvious question: do you actually need primer? Can't you just paint straight onto plastic?
Technically, yes. Your model won't explode. But here's what will happen. Your paint won't stick properly. Bare plastic is slippery, and acrylic paint sitting on a slippery surface is acrylic paint that's going to chip, scratch, and rub off the first time you handle your model. Primer gives paint something to grip. It also creates a uniform surface so your paint goes on evenly across different materials (plastic, resin, metal, gap fill, all in one coat).
Think of it this way. Primer is the foundation. If your foundation is solid, everything you build on top of it is going to be better. If your foundation is sketchy, you're fighting an uphill battle for the entire paint job.
Spray Can Primer
This is what most people use, and for good reason. Spray cans lay down a thin, even coat quickly. One pass over your models and you're done. It's the method I use for about 90% of my priming.
The technique itself is simple, but there are a few tricks that make a real difference:
Shake the can. A lot. I'm talking at least two to three minutes of shaking. You should hear that rattle ball clicking around the entire time. If you under-shake, the pigment isn't properly mixed and you'll get uneven coverage or spitting.
Use sweeping motions. Never start the spray pointed directly at the model. If you do that, you get a burst of concentrated paint right on the front of your miniature and you obscure all those details you just spent time cleaning up. Instead, start spraying off to one side and sweep across the model in a smooth pass. Think of it like panning a camera.
Multiple light passes beat one heavy pass every time. The goal is a thin, even coating that you can still see detail through. It's much better to do two or three light coats than one thick coat. If you hose the model down, you're filling in the recesses and softening all those crisp edges you worked hard to clean.
Distance matters. Hold the can about 8 to 12 inches from the model. Too close and you blast it with too much paint. Too far and the paint starts drying in the air before it hits the model, which gives you that dreaded grainy, sandy texture.
Stick your models to a piece of cardboard with poster tack, then spray inside a large cardboard box tipped on its side. The box catches overspray, you can rotate the cardboard to hit all angles, and cleanup is just tossing the box. I've done this in garages, balconies, and backyards. Works like a charm.
Product Recommendations
For spray primer, I've had consistently good results with a few options:
- Games Workshop Chaos Black / Corax White / Grey Seer. These are specifically formulated for miniatures and go on very smooth. They're also the most expensive option. If your local store carries them and you don't mind paying a bit more, they're reliable.
- Tamiya Surface Primer. Excellent stuff. Goes on thin, dries fast, great adhesion. A solid mid-range choice.
- Rust-Oleum 2x Ultra Cover Flat Black (or any flat/matte hardware store primer). This is the budget pick. A can costs a fraction of the miniature-specific brands and honestly works great if you apply it properly. The key is making sure it's flat or matte, not glossy. Glossy primer is going to give your paint a hard time.
Brush-On Primer
Spray cans work best, but there are brush-on surface primers you can use if you don't have a good place to spray. Maybe you're in an apartment. Maybe it's the middle of winter and it's minus twenty outside. Maybe you just don't want to deal with spray cans. Fair enough.
Brush-on primer takes a few layers to get good coverage, and you're going to want to thin it a little bit first. It won't be quite as smooth or protective as spray, but if you need to use it, you absolutely can. The key is patience. Thin coats. Let each one dry before adding the next. Two to three layers is typical.
Vallejo Surface Primer is probably the most popular brush-on option. It comes in a dropper bottle, thins easily with water, and goes on smooth with a brush. It also works through an airbrush if you eventually go that route.
Use a large, cheap synthetic brush for brush-on primer. Don't use your nice painting brushes. Primer is thicker than regular paint and it'll gunk up your good brushes. A big flat brush from the craft store is perfect for this. Slap it on, spread it thin, move on.
Airbrush Primer
If you own an airbrush, it's probably the best tool for priming. You get the even coverage of a spray can with much more control over how much paint goes down. You can prime indoors with a spray booth, you waste less product, and you can prime individual models or entire armies with equal ease.
Most brush-on primers (Vallejo, Badger Stynylrez, Monument Hobbies Pro Acryl Primer) work through an airbrush. Thin them slightly with airbrush thinner or water, spray at about 15-20 PSI, and you'll get a beautiful, thin, even coat.
This is the method I use when I'm doing anything that requires really precise primer application, like zenithal priming (which is a topic for the primer color theory guide).
Why I Prime Black
I prefer to prime my models black. Here's why.
When you're painting, there are always going to be hard-to-reach areas that your brush can't get to. Recesses between armor plates. The underside of a cloak. The gap between a model's arm and body. If I primed black, those spots just look like natural shadows. They blend right in. Nobody looks at a dark recess and thinks "that's unpainted." If I primed white, those same spots would stick out like a sore thumb. Bright white peeking out from under a painted surface looks ridiculous.
Black primer also means your shadows are already done, in a sense. Every recess and crevice is already dark. You're painting up from shadow, adding light where it would naturally fall. That's a very intuitive way to think about painting, especially when you're starting out.
The tradeoff is that you need more coats of paint to get full color vibrancy over black. Acrylic paint is inherently somewhat transparent, and that dark primer underneath will darken and muddy your colors if you don't build up enough layers. Always paint at least two or three coats. Even if you think the paint looks good after one coat, don't believe your eyes. Those thin layers need to build on each other to show you the true color you're using.
Temperature, Humidity, and Conditions
This is the part nobody talks about until something goes wrong. Spray primer is extremely sensitive to conditions. Spray in the wrong weather and you'll ruin your models.
Temperature: Most spray primers work best between 50 and 80 degrees Fahrenheit (10 to 27 Celsius). Too cold and the propellant doesn't atomize properly, giving you thick, gloppy coverage. Too hot and the paint dries before it hits the model, giving you that sandy, grainy texture.
Humidity: High humidity is the enemy of spray primer. Above 60-70% relative humidity, you're gambling. The moisture in the air mixes with the paint as it's in flight, causing all sorts of texture problems. If it's a muggy summer day, wait for a drier one or use brush-on.
Wind: A light breeze is fine. Heavy wind blows your spray off target and wastes product. Try to spray in a sheltered area.
Troubleshooting
Things go wrong sometimes. Here's what to do when they do.
Grainy / Sandy Texture
This is the most common problem. Your primer dried with a rough, sandpaper-like texture instead of smooth. This happens when:
- You sprayed too far away (paint dried mid-air)
- It was too hot or too humid
- You didn't shake the can enough
- The can is nearly empty and sputtering
If it's mild, you can sometimes rescue it by gently sanding with very fine sandpaper (800+ grit) once it's fully dry. If it's bad, strip the model with isopropyl alcohol or a product like Simple Green and start over. Better to strip and re-prime than to paint over a rough surface and hate the result.
Primer Peeling Off
This usually means the model wasn't clean before priming. Mold release agent (that oily residue on new plastic and resin) prevents primer from bonding. Give your models a quick wash in warm soapy water before priming, especially resin models. Let them dry completely before you spray.
Too Thick / Details Obscured
You went too heavy. It happens. If you caught it early and the primer is still wet, you can sometimes wick off excess with a clean brush. If it's already dry, you can try stripping or, if it's not too bad, just accept the slightly softer details and move on. It's a learning moment, not a disaster. Next time, lighter passes.
Before spraying your models, do a quick test burst on a piece of cardboard or a spare bit of sprue. Check the texture. If it's smooth, you're good to go. If it's grainy or spitting, adjust your distance, shake more, or check your conditions before you touch the actual models. This takes five seconds and can save you from a lot of frustration.
The Quick Version
If you just want the process without all the context, here it is:
- Clean your models (quick wash in soapy water if needed, especially resin)
- Stick them to cardboard with poster tack
- Shake the can for 2-3 minutes
- Test spray on cardboard first
- Spray in sweeping passes, 8-12 inches away, multiple light coats
- Let it dry fully (20-30 minutes minimum, ideally an hour)
- Check for any missed spots and hit them with a second pass
That's it. Your models are ready for paint.
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Now go prime something. And sometime between now and the next guide, find time in your day to slay the gray.
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