Q&A: What’s the ideal paint-to-thinner ratio?

Answer to a question: (What’s the ideal thinner-to-paint ratio?)

This question was a comment on my personal notes about how I paint skin tones.

┃Question:
When thinning Mr. Hobby (Creos) paints, do you dilute them more than a 1:1 ratio? Do you have a preferred way of thinning? Personally, I like Mr. Hobby’s Leveling Thinner.

That was the question.

Here’s my answer:

┃Answer:
A 1:1 ratio should be perfectly fine.
Basically, you don’t need to think too rigidly in terms of ratios when mixing with thinner.

That’s because ease of painting also depends on factors like your compressor pressure and whether you're mixing with clear, so there’s no one-size-fits-all answer.

So, if painting works fine with 1:1, just stick with that.
For example, if the paint scatters on the surface at 1:1, that means it’s too thin — in that case, reduce the thinner or mix in a bit of lacquer clear. The reason for adding lacquer clear is to help break down the paint particles while reducing the watery feel.

Conversely, if too many paint particles are coming out, that likely means the thinner is insufficient.
In any case, it’s essential to always test spray on copy paper before actual painting.

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To put it simply:
The fastest way to improve your workflow is to quickly figure out and memorize the thinning balance that suits your specific environment.

┃Ideally, you should minimize wasted time and unnecessary thinking.

To be honest, I don’t consciously think about the thinner-to-paint ratio every time.
As I mentioned earlier, ease of painting depends on things like the nozzle size of the airbrush, compressor pressure, whether you’re mixing in lacquer clear, and even the season (summer or winter). So it’s not something you can define with a fixed number.

Also, as paint ages after manufacturing, the solvent inside evaporates over time. That means you’ll need more thinner when diluting older paint.

On top of that, lacquer thinners come in different types for summer or winter, designed to adjust the drying speed depending on temperature.
So worrying about “ratios” ends up being a waste of mental energy...

What I really want to say is this:
If your goal is to complete a model kit, it’s ideal not to spend time or thought on things that don’t contribute directly to that goal.

This might be a bit blunt, but thinking too hard about paint-to-thinner ratios is a waste of time.
The best ratio is simply whatever feels easiest to paint with at that moment. That’s all there is to it.
If it feels too thick, thin it down.
If it feels too watery, reduce the thinner or add a bit of lacquer clear.
That’s all you need to do.

Do you think people who paint quickly and efficiently are constantly calculating their paint ratios?
Probably not. They likely don’t measure at all.
It’s just a waste of time and brainpower.
I think they’ve memorized the feel of it so they don’t have to think about these tiny details.

What truly matters is whether the paint is coming out of the airbrush at the right consistency.
That’s the key.

Of course, it’s a different story if you’re trying something new, using a method you’ve never done before, or working with water-based paints.

But for common cases, like painting with regular lacquer paints, it’s better not to overthink things.
Instead, focus on what really matters — paint consistency, how many layers you apply, your color scheme, how strong or subtle your gradients are, etc.

By the way, I posted a bit of this on X (Twitter), and it turns out a fair number of people seem to agree that overthinking it isn’t really necessary.
That said, there are also people who prefer to measure everything precisely, and that’s totally fine too.

┃In high-difficulty or high-reproducibility projects, calculating precise ratios might be necessary. However…

This is just a guess, but I get the feeling that needing such exact ratios probably applies to more advanced projects or tasks that require precise repeatability.
But let’s take a moment to think about it realistically—
At the hobby level, do we really need that kind of reproducibility or advanced ratio calculations? …Probably not.
Even when creating showcase builds, I don’t think people are worrying about exact mixing ratios.

So, there’s really no need to obsess over every tiny detail.

Oh, and while I did mention spraying on copy paper to check paint consistency, if you want to be more precise, the best way is to spray directly onto a resin part. That’s a sure thing—no doubt about it.

That’s about the kind of answer I’d give, so if you have any questions, feel free to leave a comment anytime!

I also make plenty of mistakes here and there, so if you ever catch one, I’d honestly appreciate it if you let me know.