Short answer: Streaking is a weathering technique (making a model look worn and used) where you place small dark dots on a surface and, while the paint is still wet, soften them downward with a clean, solvent-loaded brush in vertical strokes. The point is to mimic the marks rain, leaking oil and rust leave as gravity pulls them down. It works best on vehicle hulls, towers and vertical panels.
Those long, faded vertical lines you notice running down a tank's side armour or an Imperial building wall are exactly this. Streaking gives a model that "it has stood outside and something ran down it" feeling in seconds. In this guide I walk through the technique from scratch, along with the mistakes people make most and tips that actually work at the table.
What is streaking and what is it for?
At its simplest, streaking is a weathering technique that creates vertical dirt, oil, rust or water-run marks on a surface. It imitates the linear stains left behind as rainwater, leaking oil, dissolving grime or rust travel downward under gravity.
Where it works is just as clear: vehicle hulls, vertical panels, towers, walls and long flat surfaces. That is because the effect takes a cleanly painted model and gives it a story and a sense of time. AK Interactive and MIG/Ammo even make "streaking grime" enamel products built for exactly this job.
Picture it this way: the same Rhino chassis sits on two tables. One is spotless, as if it just rolled off the line; the other has a few faded dirt runs trickling down from the top panels. The second one looks like it came from a battlefield. Streaking is one of the cheapest, fastest ways to create that second feeling, because even one small detail is enough to trigger the eye's sense of realism.
How does it work?
The whole logic of streaking is gravity: liquids run from top to bottom and leave vertical marks as they dry. What's more, these runs don't start at random; they begin at the top edges of panels, at bolts, at seams and wherever water pools.
In practice, you place a small dark (dirt/rust) dot of paint on the surface and soften it downward while it is still wet. Enamel and oil-based products are ideal for this, because they dry slowly, which gives you time to soften, and solvent makes it easy to wipe away or steer the excess. That is why streaking is actually a very forgiving technique.
The key word here is "control". An acrylic wash sets rock-hard the moment it dries, whereas enamel stays open for minutes. That open window lets you place a mark and, if you don't like it, undo it, correct its direction or adjust its strength. So treat streaking not as a technique you "can't get wrong", but as one whose mistakes are easy to undo; that mindset relaxes you and encourages bolder attempts.
How do you do it step by step?
The sequence below is the typical flow for a grime run on a vehicle hull or vertical panel. Before you start, remember one thing: working on a light satin/gloss surface rather than matt lets the enamel flow more cleanly.
- Prep the surface: Lay down a light satin or gloss varnish. Enamel flows more smoothly on a slick surface.
- Place the dot: Apply streaking grime or a dark enamel/oil paint as small dots or short lines at the top points where the run will begin.
- Soften vertically: Run a clean brush lightly loaded with solvent (white spirit) over the dot in vertical, top-to-bottom strokes. Pull the paint down and thin it. One direction only: top to bottom.
- Thin and balance: If the mark is too strong, clean the brush and repeat the same vertical stroke to fade it.
- Vary it: Make some streaks long and bold, others short and faint. Avoid uniformity.
- Seal it: Once fully dry, lock it in with matt varnish.
In practice, the third step is the critical one. Most beginners struggle not with placing the paint, but with the softening brush. Too much solvent on the brush wipes the mark away entirely, while too little won't spread the paint and leaves it blotchy. The right amount is when you dip the brush in solvent and dab it gently on a paper towel, so it feels almost "damp but not dripping". Find that feel on a few test pieces first, then move to the model.
Which paints and brushes?
What really makes streaking easy is the right materials. You can do it with acrylics, but the softening window is narrow; enamels and oils are far more comfortable to work with.
- Paint: Enamel/oil streaking products (AK Streaking Grime, MIG/Ammo, 502 Abteilung oils) or oil paint straight from the tube.
- Solvent: White spirit or odorless thinner, for both softening and wiping.
- Brush: A clean, soft brush does the softening. Keep a second dry brush just to pull excess solvent off the first.
- Surface: Satin/gloss varnish first, matt varnish last.
When it comes to colour, don't overdo it. Most dirt runs aren't pure black; they're a mix of dark brown, grey-brown, rust orange and earth tones. A pure black streak usually ends up looking cartoonish. So pick a dirt tone a shade or two darker than the model's base colour and closer to nature; rust orange tends to work on metallic surfaces, and earthy brown on grey armour.
Rule of thumb: real runs are usually subtle. If you think a streak looks too dark, it almost certainly is. Fade it back — you can always add more later.
The most common mistakes
What makes streaking look fake is almost always a direction or quantity error. So avoid these:
- Horizontal or diagonal streaks: This is a violation of gravity that the eye catches instantly. Runs must always be vertical.
- Filling everything evenly: Covering the whole surface with identical streaks looks uniform and overdone. Be selective and varied instead.
- Forcing acrylics: Acrylic dries fast, so the softening window is tight. Enamel/oil is much easier.
- Overly dark marks: Fade any streak that's too strong; a thin run is always more believable.
Professional tips
These small habits are what move the result from amateur to convincing over time:
- Start streaks from logical points: the top of a panel, a bolt, a weld line, a seam. In other words, think about where water would actually run from.
- Variety in length and density is the key to realism. No two streaks should look identical.
- Enamel/oil is worth learning: slow drying and easy removal make streaking very forgiving. If you don't like it, wipe it and start over.
- Clean your brush often as you pull down. A dirty brush leaves a smear instead of a clean run.
It's best to think of streaking not on its own, but as one link in a weathering chain. It often works alongside Rust Effects — in fact, rust streaks are simply a type of streaking. The same solvent-control logic applies to Washing, Shading & Pin Wash. Streaking is mostly done with Oil Weathering: Washes & Filters, and on the lower areas of a model it blends into Mud & Dirt Effects. For the bird's-eye view of the whole subject, see Weathering: An Overview.
Frequently Asked Questions
Can I use acrylic paint for streaking?
You can, but it's hard. Acrylic dries fast, so the softening window is very narrow and you lose the chance to pull the streak down. Enamel and oil-based products, on the other hand, dry slowly, which gives you working time and lets you correct with solvent. If you're new, start with enamel/oil.
Which direction should I pull the streak?
Always top to bottom, vertically. That's because gravity pulls liquids down, which is exactly why real runs are vertical. A horizontal or diagonal streak makes a model look fake instantly. Move the brush in one direction, starting from the top point and bringing it straight down.
My streak came out too dark — how do I fix it?
First clean your brush, dip it in a little solvent, squeeze it, then run it over the mark in the same vertical stroke. Because enamel and oil are removable, you can lift the excess and fade the streak. If needed, wipe it off completely and start again — that forgiveness is the technique's best feature.
Should I streak on a matt or a glossy surface?
A light satin or gloss varnish underneath is best; enamel flows more cleanly on a slick surface and is easier to control. A matt surface, by contrast, soaks up the enamel and makes the mark harder to spread. Once the work is done and dry, seal it with matt varnish.
Where on the surface should the run start?
From where water actually pools and runs: top edges of panels, bolts and rivets, weld lines, seams and recesses. These logical starting points are what make the effect believable. A streak that begins for no reason in the middle of a flat, empty surface never looks right.
Should I streak the entire hull?
No. Filling the whole surface with even streaks looks uniform and overdone. Be selective instead: leave a few bold runs in some areas and faint, sparse marks in others. Variety in length and density is the key to realism.
How long does streaking take?
It sits at intermediate-to-advanced level and takes a moderate amount of time. The work isn't fast; it needs patience. Placing the paint is quick, but the softening and drying gaps stretch it out. Rush a wet mark and it smears. So let layers dry between passes.
In short: place small dark dots, soften them downward while wet, vary them and keep them faint. Vertical direction and subtlety are the whole secret of this technique. To try it you'll need the right enamel, solvent and a soft brush; browse the shop for paints, brushes & hobby supplies.