How do you turn a flat, factory-fresh colour into a surface that looks worn and dusty from the field? More often than not, the answer is oil paint. Short answer: oil weathering means thinning artist oil paints with white spirit (a petroleum-based thinner) and applying them in three ways — as recess shading (oil wash), as an all-over colour shift (filter), and as scattered colour transitions (oil dots). Because oils dry slowly, you can wipe, soften and correct them for hours. That is exactly why, on vehicles and busts especially, this is the most relaxed way to turn a uniform colour into a lived-in surface.
The technique actually comes from the scale modelling world, and schools like Massive Voodoo carried it into miniatures. It counts as advanced, yet the wide working window makes it surprisingly low-stress. A mistake in acrylic is permanent once it dries; in oils you simply wipe it off with a rag and start over. That forgiveness is the whole appeal.
What is oil weathering and what is it for?
Let's separate the three main uses first, because most of the confusion comes from mixing them up. An oil wash is thinned paint that flows into recesses, defining panel lines and detail. A filter is a very thin, transparent colour shift spread across the whole surface; it might pull a green vehicle slightly toward yellow or brown. An oil dot means placing several different-coloured dots on the surface, then blending them with a damp brush to create tonal variation.
The goal is the same in every case: take a flat, factory-fresh colour and turn it into a surface that looks used, sun-faded and dusty. Compared with an acrylic wash, the big advantage of oils is how forgiving they are, because their slow drying gives you plenty of time to undo a mistake.
In practice these three usually work together. First you define detail with an oil wash, then unify the overall tone with a filter, and finally add random colour variation with oil dots for depth. Layer all three on a tank's side armour and you get a lively surface where no spot looks quite like its neighbour, yet nothing jars the eye.
How does it work?
To understand the mechanics, you only need one property: slow drying. Oil paint thins with white spirit or odourless thinner, and the same solvent reopens or wipes it whenever you like. It dries far more slowly than acrylic — hours, sometimes days. That slowness is the whole trick.
Thanks to high surface tension, an oil wash flows into recesses more cleanly than an acrylic wash and leaves no tide marks on flat panels. If a dot is too strong, you knock it back with a clean solvent brush; if it is too weak, you add another. As the painter Powerfisted puts it, oils really are rich, partly because of their very high pigment load and a solvent that behaves better than water. That richness brings a second benefit too: a single tube lasts a long time, since a pinhead of paint is plenty for one miniature.
The core principle Massive Voodoo carried over is simple: there is no rush in oils. The surface stays open for hours, so the "blend, wipe, try again" loop is penalty-free — oils are a forgiving weathering medium.
How do you do it step by step? (oil dot / filter)
The flow below is for oil dots and filters. If you want an oil wash instead, the only change is to thin the paint more and carry it straight into the recesses — the rest of the logic stays the same.
- Prep the surface: Lay down a satin or gloss base first, because oils blend more cleanly and wipe more easily over a sheen. You can build that sheen with a gloss medium coat or gloss varnish.
- Place the dots: Scatter tiny dots of several colours (light sand, brown, rust orange, dark grey, a touch of white or blue). Use little; you can always add more, but pulling excess back is more work.
- Blend: With a soft brush dipped lightly in white spirit and then wiped on paper towel, drag over the dots in a single direction (usually top to bottom). The aim is to spread the dots into a thin coloured "haze" over the surface.
- Check: Step back and look; if it reads too strong, fade it with a clean solvent brush, and if too weak, add dots. Don't trust a single pass — the effect usually settles over a few rounds.
- Wait for it to cure: Oils dry slowly, so be patient — hours, sometimes a day. Don't touch a half-dry surface or you'll leave marks you can't fix later.
- Finish: Once fully cured, seal with matt varnish. Varnishing too early wrecks the surface, so don't rush this final step.
Which paints and brushes do you need?
The good news is that you don't need an expensive set; a small investment buys a big jump in quality.
- Artist oil paints: Winsor & Newton, 502 Abteilung, or AK/MIG oilbrushers all work. A pinhead of paint lasts a whole miniature.
- White spirit / odourless thinner: Choose the odourless kind for indoor work.
- Soft brushes: A soft, full brush for blending; a fine-tipped brush for the oil wash.
- Card or paper towel: Used to draw off excess binder oil from the paint. This small step leaves the paint matter and faster-drying.
- Gloss and matt varnish: One for the gloss base, one for the matt finish.
The most common mistakes
Most problems trace back to four common slip-ups, so knowing them up front saves you half the trouble.
- Flooding solvent-heavy oils onto bare acrylic: The solvent lifts the acrylic. Seal it with varnish first, then apply the oils.
- Over-blending the filter or dots: Work it too long and the subtlety vanishes — everything melts into one flat stain. A filter must stay thin.
- Varnishing before the oils cure: The surface wrinkles and goes dull. Wait for a full cure.
- Using solvent in an unventilated room: That's a health risk. Open a window or run a fan.
Pro tips
What separates a good result from a flat one is usually a few small habits, and the ones below make a visible difference.
- Before using the paint, draw the excess binder oil onto a piece of card for a few minutes. The paper soaks up the oil, leaving the paint matter and faster-drying.
- A gloss base means clean washes and easy wiping; a matt base "grabs" more but is hard to correct. If you're new to this, start on a gloss base.
- Don't build a filter in one hit. If you need more, shift the colour slowly with a few thin filters, leaving drying time between them.
- A filter is really a kind of transparent colour pass, so it helps to think of it alongside Glazing. In the same way, an oil wash is the most controlled form of Washing, Shading & Pin Wash.
- Pull vertical oil streaks to add Streaking & Grime, or use rust tones to build Rust Effects. For the bigger picture, see Weathering: An Overview.
Frequently Asked Questions
What's the difference between an oil wash and a filter?
Both are made with oil paint, but their jobs differ. An oil wash is a local application where thinned oil paint flows into recesses to give shade and define detail. A filter is a very thin, transparent colour shift spread across the whole surface; it adjusts overall tone rather than adding shadow. In short, a wash sharpens detail, while a filter unifies and revives the entire colour.
Which solvent is used for oil weathering?
White spirit or odourless thinner; if you work indoors, choose the odourless version. This solvent both thins the paint and lets you wipe it off the surface even hours later. Water and acrylic thinner won't work here, because oil paint only reopens with a petroleum-based solvent.
Can I do oil weathering over acrylic paint?
Yes, but you must seal the acrylic with a coat of varnish first. If solvent touches bare acrylic directly, it can lift the paint. To prevent that, build a barrier with gloss varnish; this protects the acrylic and helps the oils blend and wipe more cleanly. Skipping this step is one of the most common mistakes.
Can I varnish before the oils dry?
No. Oil paint dries slowly — hours, sometimes days. If you apply matt varnish over uncured oils, the surface wrinkles, dulls and the effect is ruined. The safest move is to wait a day. If touching the surface leaves no mark, it has cured and only then should you varnish.
My filter came out too strong, how do I fix it?
This is exactly what the forgiving nature of oils is for, so there's no need to panic. With a clean brush dipped lightly in white spirit and wiped dry, soften and fade the excess colour. If it's very strong, wipe it off completely with a solvent rag and start again with less paint. Unlike acrylic, there's no permanent mistake here.
Is this technique only suitable for vehicles?
No, but it shines brightest on vehicles and busts, where the broad flat surfaces are ideal for filters and oil dots. You can use recess washes and a gentle filter on standard 28-32mm figures too, though the effect stays more subtle on small surfaces. Large armour panels and cloaks are the best canvases for this technique.
Takeaway: All the power of oil weathering comes from its slow drying; don't rush, work in thin layers, and apply it knowing you can always correct it. To get started you need a few tubes of artist oils, a bottle of odourless thinner and a soft brush. To kit out your bench, browse our paints, brushes & hobby supplies.