How to use Mr. Hobby Acrylic paints with the airbrush?

Greetings fellow scale modelers,

Today I was airbrushing my Armored Carrier from Tamiya for the first time of being inactive with model making and airbrushing.
And I was wondering, how do I use Mr. Hobby acrylic paints with my airbrush?
I’m talking in this case about the H-40 Flat Base paint.
But I would also like the advice in general.
How do I thin my Mr. Color Acrylic paints down using their 110 Aqueous Hobby Color thinner?
I have done a quick search on YouTube, but the answer isn’t really shown that clear to me.
One video states that it is one to one or one to one and a half.
But I don’t know, help is really much appreciated in this topic.
If this topic is better placed in another place on the forums, feel free to move it.
I hope you can help me in this matter.

I thin my Mr.Hobby Acrylic paints in roughly 1:1 ratio.
I say roughly, because I don’t measure paint and thinner.

Good rule of thumb is- when you open a new bottle of Mr.Hobby top it up with Thinner(the one you mentioned, or the splendid T106 Mr.Hobby Levelling Thinner), then stirr gently, close the bottle and shake it .Fill some in your AB cup and try it out.
This has always worked for me.

1:1.5 thinning ratio will also work, but then you might need to spray with lower pressure and you will need to lay the paint in multiple passes.I use this ratio when spraying Mr.Surfacer primers.

Bear in mind, that Mr. Hobby’s Aqueous thinner will work with Tamiya’s Acrillyc paint ranges too, but you should never use it for Mr.Color paint range.
On the other hand- T106 Mr.Hobby Levelling Thinner will work with Mr.Hobby Acrylic paints, Mr.Color paints and both Tamiya Acrilic and Lacquer paints.


Sounds like testing is in order. Try a few test runs painting white plastic spoons. That will let you test what works best for your air brush and conditions. One can add a little thinner and vary air pressure to get dialed in for best results.

Best wishes with the project.

Guys I think you are giving advice on the wrong product.

MBL… May I ask what are you looking to use this for? As a top coat over the base colours (as the guys before me have assumed) or for adding to a non-matt paint to make it a matt colour?

H-40 is Flat Base and is meant to be mixed with gloss paints to give a Flat colour.

H-20 Flat Clear is their ‘top coat over paint’ finish product that I think may be what you need…

Mr Hobby Blurb on H-40…
“Gloss levels obtained using gloss coat Aqueous Hobby Colors can be adjusted by using H-40 Flat Base - mix approximately 5% to 10% of H-40 Flat Base to convert gloss colors to a matt finish, or up to 5% for a semi gloss finish. The percentage of Flat Base used can be adjusted to vary the amount of gloss level obtained.”

Using H-20 as a top coat, I mix roughly equal quantities, clear to thinner, as mentioned above. However, Do Not lay down a heavy coat. Lay down a thin light coat and allow to dry. Repeat the light coats until you get an effect where you think one more coat will do it - then STOP! I guarantee if you do that extra coat, you will end up with a milky white tinge to your model… and if you lay down a single heavy coat, you will get a milky white build up in corners and around details, if not a coat of clear that looks like a film of ice…

…and as suggested, always do a test on scrap plastic before starting on your model.

Thank you for your reply.
I was inteding it to use it as a coat to seal my paint work and decals in.
I had in my opinion clearly explained to the shop owner on the phone, that I wanted to do that.
And he said they had H-40 from Mr. Hobby that I could use to seal things in etc.
Maybe he confused H-40 and H-20 as I’m reading in here.
So I can’t use H-40 to seal things in? It is not designed for that?
What can I do now then? I’m not really the guy who experiments a lot as I see that as wasting material and time.
Also I don’t really a lot about the different paint brands.
I have always used Revell enamel paints.
So all the other paints are relatively new to me.
Maybe it is usefull if you provide me with internet links and knowledge that I can learn?
So that I can make better decisions on my own?
Anyway thank you for your reply.


Thanks for suggesting testing first on plastic spoons.
I will see what we have and I might give it a try.
Thanks again for the suggestion.


Whilst there are video’s out there if you google for them, the big underlying factor is you and your equipment. There are many variables - needle size, gravity fed or suction cup, type of air brush, source of compressed air (aerosol, direct pressure pump or storage tank), etc. Then there is the temperature you spray in, humidity, how heavy handed you are with the AB, etc.

So in reality, the best solution for you is to practice. Cost of paint not withstanding, it is better to ruin spoons or scrap plastic/models with your testing, than ruin the model you just built.

I would not use the H-40 you have as it will likely ruin your model. Get some H-20 or Tamiya Flat Clear for acrylic top coats.

Acrylics dry fast, so low pressure light coats sprayed with the AB close to the model works best. High pressure will flood and splatter paint if sprayed too close, and you will get a gritty, grainy effect if you spray from too far away, as the paint actually dries during the transit from AB to model. Thin either of the suggested paints by equal quantity of their thinner (for Tamiya I use their lacquer thinner, not acrylic thinner for a much smoother finish) and spray on pressure around 12-15 psi first, then work up the pressure or change the paint viscosity from there based on how your AB and air source perform on your test pieces.

Good luck. I hope you get the result you are looking for.

What is paint viscosity?
And what is 12-15 psi in bars?
I’m usually working on with a pressure of two bars.
And I’m also still have to adpopt the thought that I need to work with layers instead of spraying one thick layer on to get the work done in one go.
It seemed with Revell enamel paints that I could get the job done with one carefully sprayed layer of paint.
But it may be different with the acrylics.
I had with Revell enamel paints that I had one part thinner and one part paint. Not in this specific order.
I will see what I can do to do more practice and testing. And I will be doing more research online for questions I might have.
But I’m also seeing the forums here as the central point of information, where I can post my questions and get information.
To use that more to do searches on the internet, as I’m not always knowing the right search terms to enter.
Also, I’m using for my searches. As they are privacy respecting and are respecting the user instead of seeing them as a product to make money of.
Anyway, thanks for your reply.


To work out PSI:

12 PSI = .83 bar
15 PSI = 1.03 bar

Viscosity is a term for liquid that basically means how ‘thick’ it is. High Viscosity means it is very thick, say like honey, where a low Viscosity means thin, like milk or water…

You can spray some acrylics like Tamiya paints in one layer but not others. AK, MIG or Vallejo really need to be sprayed in light layers or the paint will not be smooth -it will bead, look like orange peel or other ‘bad things’!

Even with Tamiya paints the best results are done with thin layers. This lets you add more or less paint in some areas, which gives a subtle variation in the depth of colour. It also makes sure you do not get a thick build up around details.

With thin paint you can pre-shade (make corners and areas around fittings, etc, a darker shade) by spraying a thin coat of a dark colour (or light colour) in certain areas first, then spraying your base colour in thin layers over that so the pre-shade colour makes your base colour darker or lighter in some areas.

Pre-shading demonstration:

Painting the base colour over the pre-shade

If you are new to using acrylics, I would stick with Tamiya or Gunze. They are the most forgiving paints for novice users. Once you have mastered using them, with low pressure, thin coats, etc, then you can look at others.

HOWEVER, no matter what type of [paint you use, the clear top coat should always be thin layers to avoid white build up. Even Dullcoat from Testors can react badly if too thick - I know that from experience.

Thank you for replying so many times on my topic. And that you are giving me so many good advice and information. It is really really appreciated, since I’m not that knowledgeable about airbrushing. I now just have the thought, if it just works its fine to me. So all the help, tips etc. Are welcome to improve my works even more. I didn’t watch the video’s, I will do that when I get home. I will give seperate reaction on that. I will be more trying and testing out. And I’m looking forward doing that.

Thank you so much for replying and the great tips and information.

Modelbouw Nederland.

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