Are you looking for a fast and easy way to paint the armor panel lines on your miniatures? The thin, narrow panel lines you find on miniatures like Gunpla, Warhammer 40k armored units, or military scale model vehicles, aren’t easy to paint. For best results, the panel lines should be painted with a dark paint, a method also known as “dark lining.” While a long, thin bristled paint brush can help, what if I told you there was a faster way to dark line panels without needing a steady hand or fancy tricks?
In this post, I share how I use watercolor paints to quickly and easily dark line the panel lines on your models. This is also a great method to shade hard-to-reach recesses on your miniatures.

Key Takeaways
- Watercolor paints offer a fast, affordable alternative to oil washes for dark lining panel lines in miniatures.
- Watercolor paints are applied late in the painting workflow, ideally after acrylic base layers are complete.
- Watercolor pencils are better suited for edge highlighting than for dark lining recesses.
- Applying a clear varnish coat before and after using watercolors can protect the integrity of your paint layers.
- A gloss varnish is preferable if you opt to varnish before applying watercolors, as it aids in the flow of the pigment.
- When preparing watercolor paints, aim for a slightly thicker consistency to enhance pigment density for better dark lining.
- Cleanup involves reactivating watercolor pigments on unwanted areas and gently removing them, preserving the paint in recesses and panel lines.

Three Recommended Watercolor Paint Sets for Painting Scale Models and Miniatures
- ARTEZA Gouache Paint Set (Full Premium Set)
- SAKURA Koi Pocket Field Sketch Kit (My Favorite)
- HIMI Gouache Paint Set (Popular, Budget Set)
I’ve tried a bunch of watercolor brands. But I realized that for miniature painting, almost all of them will serve us well. You don’t need a lot of colors, so you don’t need a big set. The most important feature is that you have easy access to your watercolor paints.

Most of the time, you’ll rely on acrylic hobby paint to finish your miniature painting projects. Watercolor paints come into play much later in the painting workflow; when you’re ready to add weathering, special effects, and of course, darkening those panel lines.
If you’re wondering about using watercolor pencils, then you’re on the right track for other techniques you can use with the watercolor media. However, watercolor pencils are best used for edge highlighting, rather than dark lining deeper recesses on your models. I discuss the use of watercolor pencils more in-depth in this article.
Read on to learn how I use watercolor paints to dark line and paint panel lines on miniatures.
Why I Love Watercolor Paints for Painting Tabletop Miniatures
I am always looking for shortcuts to paint miniatures more efficiently. One technique that has sped up my workflow was learning how to use oil paint washes to shade my miniatures.
The workflow with oil paint washes is to apply the darkening oil pigment color over an acrylic basecoat, allowing the solvent to evaporate–often mineral spirits–and cleaning up the residual oil paint color only on the raised surfaces of your model.

This process leaves behind the oil paint in the deeper recesses, in the panel lines, too, which gives the model depth and a grimier look overall. The end result is a beautifully shaded miniature in very little time.

Of course, oil paints are messy, require special solvent to thin properly into a wash consistency, and you’ll need to maintain a separate brush set apart from those you use for painting with acrylics (e.g., water-soluble hobby paints and oil paints don’t mix). And, yet despite these limitations with oil paints, the results are fantastic!
Is there a way to replicate the oil paint wash workflow on miniatures without the mess and complications?
Yes! With watercolor paints, you can achieve a similar effect in less time and with less mess. Instead of dissolving your wash pigment in a volatile solvent, as required when you’re using oil colors, watercolor paints use…well, water!

You’ll need to be aware of a few simple tricks, which I’ll show you below. But once you get the hang of using watercolor in your miniature painting special effect steps, you’ll wonder why you didn’t try it sooner.
Here are a few key reasons why I started using watercolor paints:
- Watercolor paints are affordable
- Plain water serves as the paint solvent, so it fits perfectly with what you’re doing already with hobby acrylics
- It’s a fast process, and you can clean up any mistakes
- Watercolor paints come in a huge number of colors
A limitation of using watercolor paints, however, is also its greatest strength: watercolors dissolve readily in water. So, for the longevity of your paint job, you’ll have to be careful to protect your finished project with a proper varnish.
A clear coat sealant should always be used after you apply a watercolor wash. Once your watercolor paints dry, and you’re done with your paint job, make sure you apply a thin coat of sealer. This will allow you to continue painting more layers on top, whether it is more watercolor or acrylic paint.
Here’s how you paint darkened panel lines on your miniatures with watercolors.
Step 1 – Paint your model with acrylic paints
Before you apply any watercolor paints to your miniature, you’ll want to make sure you’ve finished painting as much of the model with your acrylic paints as possible.

Watercolors are wonderful as an “add-on” media for acrylic painted miniatures. But, because watercolors are transparent by nature, you’ll find they aren’t very good at hiding any underlying color.

Make sure you completely paint your miniature as much as possible using techniques and methods that you normally would. Here, I’m painting a Warhammer Tau XV25 Stealth Battlesuit from Games Workshop.
I find that watercolors work best when you start with a bright underpainting.
When you start with a brighter paint job, the overlying watercolor will naturally darken the surface–even after you wash most of the watercolor off (see below). In fact, any surface you think is too bright will look much better after you apply a watercolor wash.
Overall, feel free to paint your miniature as you normally would with your favorite hobby acrylic paint brand, e.g., Citadel, The Army Painter, Reaper Paints. Watercolors will work well on any of these painted surfaces.
Step 2 – Apply a thin varnish (optional)
Do you need to varnish your painted miniature before applying watercolor paints? This is a common question I got from my YouTube video about how to paint miniatures with watercolors. Well, my answer is not really, but it helps reduce the risk of rubbing off underlying paint layers.

As part of the process of using watercolor paints, you’ll need to wipe or rub off excess pigments after the paint has dried. Here, a clear coat layer applied before the watercolor application step will protect underlying layers from abrasion, and could help the watercolor pigments flow where they need to go–that is, into the recesses.
In case you were wondering, I don’t use a varnish at all when I use watercolor paints as part of my miniature painting workflow. It’s an extra step that takes extra time (that I don’t want to spend), and could if not done carefully reduce the fine details in your final paint job.

Varnishes tend to be “thicker” than regular paints, so they will “fill in” detail texture on your model, resulting in a less crisp-looking final product. So, if you feel comfortable with your ability to use a light touch when wiping away excess pigments from the watercolor application, then forgo the varnish.
On the other hand, if you want to keep your underlying acrylic base colors intact, reducing the risk of damage as you work with overlying washes, then a good varnish coat will achieve your goal. It may also help the watercolor go where you want it, especially if you use a gloss varnish.
Gloss or matte varnish?
This brings me to the next common question: “Gloss or matte varnish?” you may ask when applying watercolor paints over your models. When using varnishes or clear coats as a protective layer between other art media, such as watercolors or even oil paints, I always use a gloss varnish. Gloss varnishes tend to be more durable and will provide that “slippery” surface to help washes properly shade your model.

If in doubt, use a gloss varnish when you’re combining acrylic painting approaches with watercolor paints on your miniatures.
At the end of your miniature painting process, you should use a matte varnish to create an even non-reflective surface. To learn more about best practices and uses of varnishes in miniature painting, check out this simple varnishing tutorial painting miniatures.
How to apply a varnish before watercolor painting your miniatures
There are many kinds of varnishes for miniatures. The easiest kind of varnishes to use are water-soluble varnishes, like those from Liquitex or Golden. You can apply them with a regular brush, or thin them down with regular water to airbrush them on your models.

When you’re using a varnish to coat your models before applying watercolor paints, you need to make sure you apply a super thin layer. To do this well, I suggest you spray your varnish onto your model using an airbrush at low pressure.
Thin your water soluble varnish until it is similar to a milk-like viscosity (this usually means mixing water into your varnish from the bottle in a 1:1 ratio). Using your favorite airbrush, spray an even coat of the varnish over your entire miniature at low air pressure (20-25 PSI).
Make sure to hold the nozzle about 6-12″ away from your model to make sure none of the varnish pools in a small area.
Then, allow the varnish to dry completely. Use can use a hair dryer to speed up the process, which I do all the time because I want to reduce the risk of any random dust or dirt sticking to my wet varnish application.
This layer of varnish will help your watercolor wash flow properly over your model and act as a protective layer for subsequent work on your miniature.
Step 3 – Prepare your watercolor paint
All watercolor paint needs to be thinned before use. Take your brush, dampen it in a bit of clean water from your paint rinse cup, and wet the watercolor pigment.

For darkening and painting panel lines on your models, you can use black or any dark color you want. I chose black for my project because I want strong contrast, separating each panel of armor from its neighbor.
You want your watercolor wash to be a tad thicker in consistency than if you were to paint with it, traditionally. The idea is to keep the pigment density high, which will help darken the panel lines.

The type of brush doesn’t matter much here. Just make sure it holds a good amount of watercolor and you have good control over the bristles.
I like using a size #2 pointed round sable or synthetic brush for applying watercolor to my miniatures. A brush like The Army Painter Regiment is a good choice, or something similar in size and feel works well for applying watercolors to your models.
Now, the fun part.

Paint the panel lines with your paint brush loaded with the watercolor paint. It’s okay to be messy. Paint all the nooks and crannies on your model, making sure that the watercolor paint seeps along the panel lines.

It’ll look haphazard at first. But, in the next step you’ll clean it all up and it’s going to look great! Allow each layer of watercolor paint to dry before applying more or doing touch ups.

Once you’re done, allow all of the watercolor paint to dry. The pigments on the model should look matte (non-reflective) all over the model.
Step 4 – Clean up excess watercolor paint
To finish the job, dampen a clean brush in water. Make sure the brush is only damp, not dripping wet. You want to reactivate the watercolor paint on the raised surfaces and flat parts of your model without affecting the paint that had dried in the recesses and within the panel lines.

Use a gentle touch and slowly dab the areas of the model where you want to remove watercolor pigments. You’ll notice that when you wet these areas, the watercolor becomes more fluid-like and will spread around in these areas.

With your brush “erase” the watercolor from the surface, wiping it away in small sections at a time. You may want to dry your brush on a clean paper towel to help this process along. You can also use a separate “clean” brush to wick up the solubilized watercolor from your model.

The key here is to try and let the pigments remain in the recesses, as this creates a natural shadow effect. It’s okay to be messy here and there. The goal is to reveal more of the brighter original painted undercoat, which will contrast with the darkened panel lines and recesses on your model.

A trick I’ve tried with success on some models, if the watercolor doesn’t come off quickly enough for you, is to use cotton-tipped applicators or cosmetic sponges. I like the cosmetic sponges because a small piece goes a long way, and in some cases are re-usable.

This technique will take practice, but the process is simple. Just remember that you are using your brush like an eraser!
Step 5 – Seal with a Matte Varnish
After you clean up your excess watercolor paint, it’s time to seal everything in with another thin layer of varnish.
This can be the same water-soluble kind as before, or any other type of sealer you prefer. For the best durability, especially if you’re planning to use your miniatures in a tabletop game, travel with it, etc., is to use an enamel-based matte varnish. Testors Dullcote is all I use.

This final varnish layer will protect all the work you put into watercolor painting those panel lines. And, if you want to, you can keep painting over the varnish without disturbing your prior work.
Bonus Step – Apply Edge Highlights for High Contrast
Watercolor paint washes tend to darken the surface of your model. Even if you remove most of it, the overall finish will appear darker than the original paint color. This would be true even if you used oil paints as a wash, too.

To restore some of the brightness to your miniature after using watercolor paints, I like painting the edges of different elements on the model. Edge highlighting gives back some of that lost contrast, drawing the eye toward larger shapes and volumes.

Highlights help make your miniature standout a bit more from the background.

As someone who enjoys taking photographs of finished pieces, edge highlighting also helps make your captured images look better. It’s easier to photograph a model with strong color contrast between the edges, as opposed to a model that has been watercolor washed and doesn’t have some of those highlights popping out.

How you apply edge highlights is a matter of personal preference, style, and context. For this particular model, I used an off-white color (e.g., Vallejo Model Color Ivory) mixed with the original basecoat for highlighting the edges.

Interesting observations with watercolor painting miniatures
- Your final results may vary depending on the kind and color of watercolor you use, how much time you put into clean up, and the model you’re painting.
- Watercolor dries with a matte finish and may create an uneven surface. You can use a varnish clear coat to even out any changes in reflectivity on your model.
- If you’re looking for a grimdark aesthetic, then watercolor or oil washes are your best friend. Either of these mediums dry with a matte finish, come in wonderfully muted colors, and help create realism and depth on miniature models.
- The beauty of watercolor painting is that you can use it to create gradients and give a model an aged “worn” look by modulating color intensity in very select places, e.g., rust, oil leaks, and more.

Conclusion
What do you think? Fun? Inspired? Watercolors are fascinating for miniatures.
If you’re looking to add depth and interest to your miniature painting without going through a complicated process, using harsh solvents, or using special equipment, then using watercolor to shade recesses and paint panel lines is definitely a technique worth trying out!
It’s a quick and easy way to add contrast and make your models stand out on the tabletop. Plus, because watercolor washes off with a simple dab of water, it’s a fun way to experiment with different color combinations and create unique effects on your miniatures.
As with anything we do in miniature, a huge draw is discovering new ways to do cool things. Watercolor has emerged as one of those techniques that I love experimenting with. I’ve slowly used it more and more in my work. Give it try!
Are you curious to try something new with your miniatures? Watercolor may be a fun new tool for you.
Did you enjoy this article? I’m always looking for feedback and would love to hear from you. Leave a comment below!



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