Short answer: Airbrush zenithal preshading is the technique of building a black-grey-white light-and-shadow map with an airbrush before you apply any colour. It mimics light from above, and the transparent colours you spray on top then inherit ready-made shadows and highlights from that map. In short, it is a fast, clean base workflow that is especially lethal with Contrast paints.
Think of it as one of the biggest time-savers on the painting table. That is because the airbrush's gradual spray builds, in minutes and with no streaking, the transitions that would otherwise take hours by brush. Below I walk through both zenithal and classic pre-shading, the steps, the materials and the traps people fall into most.
In terms of difficulty, this technique sits at a medium level, so even someone new to the airbrush can pick it up after a few practice passes on a scrap piece. Once you grasp the logic, you can scale the same workflow up to whatever you like — whether you are painting a single hero miniature or a whole army.
What is airbrush zenithal preshading and why use it?
To begin with, we are grouping two related techniques under one heading. Zenithal assumes light comes from above and builds a value map (a tonal map) that runs from a black base up to white high points. Pre-shading, on the other hand, sprays dark lines into recesses and panel lines before colour, so the semi-transparent colour on top reads those lines as shadow.
As you can see, both rest on the same principle: the value underneath sets the brightness of the colour on top. In other words, you "build" the shadow and the light before painting, and then add only colour. For the foundations, see Zenithal Priming and Pre-Shading & Post-Shading.
How does it work?
This is where the airbrush really earns its keep: it gives a far more controlled, gradual and smooth gradient than a rattle can. As a result, in zenithal the black-to-grey-to-white transitions settle in with no brush marks at all.
Then, when you lay a transparent colour on top — a wash (a thin shading paint), a glaze (thin transparent paint), or Contrast/Speedpaint — the paint is see-through, so the dark-light information underneath bleeds up to the surface. Where there is black in a recess, the colour reads dark there; where there is white on a crest, the colour reads bright. Pre-shading is the same idea borrowed from aircraft and vehicle modelling: dark panel lines grin through from under the colour as shadow.
In practice, these two approaches often merge. First you build the zenithal value map, and then you add a little extra pre-shade into the specific recesses that need it. That way the airbrush handles both the overall volume of light and the local shadow depth in one session, and by the time you reach for the brush only colour and final touch-ups remain.
As Miniatures of Death puts it: "After laying an even coat of black primer with the airbrush, gradually apply white primer spatters from the top of the miniature." That really is the whole logic — keep the black, and dust white only on the very top.
How to do it step by step (Zenithal)
Whether you are working on a single mini or a whole tank, the same order applies. Just don't rush; let the airbrush finish its job — that is, let the paint dry — between coats.
- Black base: First, cover the entire model with black primer or paint via airbrush. This will be your deepest shadow.
- Grey (45°): Next, spray grey from above at roughly a 45° angle. Top and side surfaces go grey, while the lower recesses stay black.
- White (from the top, sparingly): Finally, apply white only from directly overhead, at a steep angle and in small amounts. Only the highest raised areas should whiten — leave the rest alone.
- Check: Now step back and check: are the transitions smooth? Are the deepest recesses black and the highest points white? If so, your map is ready.
How to do it step by step (Pre-shading)
Pre-shading really shines when you plan a light base colour. That is because the lighter the colour, the more clearly the dark lines underneath read as shadow.
- If you are planning a light base colour, first spray thin dark lines (black or dark grey) into the panel lines and recesses.
- Then lay the semi-transparent base colour on top in thin passes, letting the dark lines show through as shadow.
- Finally, check the shadow depth; if it is too faint, sharpen the dark line a touch, and if it is too strong, build one more pass of colour over it.
Which paints and airbrush settings?
The good news is that you don't need an exotic shopping list; the right viscosity and low pressure solve most of it.
- Primer/paint: Black-grey-white airbrush primer or well-thinned acrylic. The Vallejo, Citadel and Army Painter airbrush ranges are standard picks.
- Top colour: Highly transparent Contrast/Speedpaint paints, or acrylic thinned to a glaze. A zenithal map pays off most with these.
- Thinning: The "two thin coats" logic applies here too; aim for a milk consistency through the airbrush. See Thinning Paint: Two Thin Coats.
- Pressure and distance: Low pressure (around 15-20 psi) and a few centimetres of distance. Spraying too close leaves blotches.
Most common mistakes
Whatever ruins this technique nearly always falls into the same four buckets, so knowing them up front lets you avoid most of the trouble.
- Spraying white over too wide an area: When this happens, all contrast is lost and the model looks grey and flat. White should go only on the very top points.
- Holding the wrong angle: Light it from the side and the zenithal logic breaks. Light must always come from above.
- Laying the top colour too opaque: In pre-shading, if you cover the dark lines completely, all that pre-shade is wasted.
- Spraying too close: The result is blotches, splatter and a textured surface. So keep your distance and pressure steady.
Pro tips
A few small touches push the result a notch past amateur.
- Warm tones instead of pure black-white: The well-known Tale of Painters hack — go from a warm dark grey base to a light ivory rather than pure black and white; skin and natural surfaces in particular settle far more realistically.
- Contrast/Speedpaint on top: One transparent coat over the zenithal map equals instant shading and highlights. For more, see the Contrast & Speedpaint Systems guide.
- Don't overdo pre-shading: Thin, selective dark lines are enough. Darken the whole surface and the effect vanishes completely.
- The brush alternative: No airbrush? Start with the Slapchop technique, which is the drybrush (dry-brush) version of the same logic.
Frequently Asked Questions
Are zenithal and pre-shading the same thing?
Not exactly, but they are close cousins. Zenithal assumes overhead light and builds a black-grey-white value map. Pre-shading sprays dark lines into recesses and panel lines before colour, so the transparent colour on top inherits the shadow. In the end, both rest on the principle of building shadow before you paint.
I don't have an airbrush — can I still do this?
Yes, you can. The brush version of the same logic is Slapchop: black primer first, then grey and white drybrush (dry brush) to build a value map, and finally Contrast on top. A spray-can primer also works, but it won't give a gradient as smooth as an airbrush.
Which paint should I put over a zenithal base?
The strongest combo is transparent paints: Contrast, Speedpaint, washes or acrylic thinned to a glaze. Because they are see-through, the light-shadow information underneath bleeds up to the surface. By contrast, spray an opaque paint and your zenithal map disappears, wasting the effort.
How wide should I spray the white?
As little as possible. White goes only on the highest crests where light hits directly, at a steep angle and in thin passes. The most common mistake is spreading white over a wide area, which kills all the contrast and leaves the model looking flat grey.
What airbrush pressure should I use?
Around 15-20 psi and a few centimetres of distance usually works. Lower pressure gives more controlled, fine lines. By contrast, spraying too close or at high pressure causes blotches, splatter and a textured finish, so test on a scrap piece first.
Should I use pure black and white?
Not necessarily. As Tale of Painters suggests, going from a warm dark grey base to a light ivory looks more natural on most surfaces. Pure black-white contrast can read harsh and cold, whereas warmer tones sit better, especially on skin and organic surfaces.
How long does this technique take?
The painting itself is a matter of minutes — the real wait is drying time. That is because between each coat (black, grey, white) you wait for the airbrush primer to dry. Even so, you can build a base in under half an hour and bring a model to tabletop standard with a single Contrast coat on top.
Key takeaway and next step
Let one sentence stick: build the shadow and the light before you paint. Keep the black base, lay grey at 45°, dust white only on the very top, then spray transparent colour over it and let the map do the work. As you'll see, this workflow is both fast and clean.
If you want to start with the right airbrush primers, Contrast paints and thinners, build your own kit from the paints, brushes & hobby supplies in the shop.