Prime Time — Why Your Undercoat Is the Foundation of Everything

Stephen Ramsey
May 7
3 min read

You've assembled your model. You're excited. The paints are out. You pick up a brush, dip it in black, and start going. Six hours later your masterpiece is done — and two weeks after that the paint is flaking off in chunks, revealing bare grey plastic underneath.

This is the primer story. Almost every beginner skips it at least once. Almost every beginner regrets it. The good news: it takes about two minutes and costs next to nothing.

What Primer Actually Does

Bare plastic — the stuff your Warhammer models are made from — is smooth, non-porous, and slightly oily from the moulding process. Acrylic paint has nothing to grip onto. It looks fine when wet, but as it dries and flexes, it peels. Primer creates a micro-rough surface that acrylic paint bonds to both chemically and mechanically. With a good prime coat, your paint will stick, stay, and survive the knocks of a gaming table.

Beyond adhesion, your primer colour sets the tone for your entire colour scheme — and choosing the right one is where the real craft begins.

Choosing Your Primer Colour

This is where beginners get surprised: the colour of your primer changes how your finished model looks. Significantly.

Black primer — shadows are already done for you, very forgiving of patchy coverage, makes colours deeper and more muted. Perfect for dark armies, Chaos, undead, and Nurgle. Also the starting point for Slap Chop (see Blog 3).
Grey primer — the balanced choice, works with almost any colour scheme, neither as forgiving as black nor as vibrant as white.
White or Wraithbone primer — makes colours pop and stay bright, essential for yellow and orange schemes, Contrast paints work best over a light primer.

Not sure which to pick? Start with black. It's the most forgiving for beginners — any thin patches just look like deep shadow. It's also the base for the Slap Chop technique we cover in the next post.

How to Prime — The Right Way

Spray Primer (Recommended)

Spray primer is the fastest, most even method. Citadel's Chaos Black spray is the hobby standard, but any acrylic spray primer in black, grey, or white will work fine.

Check the weather. Don't prime in the rain, in direct sunlight, or in temperatures below 10°C. Cold, damp air ruins primer — it goes chalky or grainy. This is North Tyneside, so plan accordingly.
Hold the can 20–25cm away. Too close means runs and drips. Too far means chalky, rough texture.
Short, sweeping passes. Don't hold still. Keep the can moving across the model.
Rotate and repeat. Spray from multiple angles to catch undercuts and recesses.
Let it dry properly. At least 30 minutes, ideally overnight before painting.

Frosting warning: if your spray-primed model comes out looking dusty or chalky white, it's been primed in conditions that are too cold or too humid. Strip the model and try again on a better day.

Brush-On Primer

If spray priming outdoors isn't an option, brush-on primer is a solid alternative. Apply thin coats — two coats is usually better than one. Use an old brush rather than a good one. Citadel's brush-on primer or Vallejo Surface Primer are both excellent.

The Artis Opus Angle — Why Surface Prep Matters Even More With Good Brushes

Artis Opus make some of the finest brushes available to hobby painters — their Series S and Series M ranges use genuine Kolinsky Sable hair and are handmade in the UK. But their content consistently emphasises: even the finest brush in the world can't rescue a poorly prepared surface. A smooth, even prime coat lets your brush do what it's supposed to do — carry paint smoothly from bristle to surface without resistance.

Priming Resin and Metal Models

Resin — wash in warm soapy water first to remove mould release agent, dry completely before priming. The release agent acts like a barrier and will cause paint to reject.
Metal — lightly roughen with fine sandpaper before priming, or use extra coats of standard primer.

Two minutes with a spray can now saves six hours of repainting later. Prime your models. Always.

Next up: Blog 3 covers Slap Chop — the technique that's changing how hobbyists paint entire armies. Publishing Monday 11 May 2026.