How to Thin Acrylic Paints Properly

Acrylic paints are probably the most popular paints for any kind of crafts or art project out there. They are so popular because it’s easy to work with them, acrylic paints dry fast, are water-soluble while still being water-resistant once they dry. So they are a perfect fit for a lot of crafting and art-related projects. But a lot of newcomers and even some veterans do a lot of things wrong when thinning acrylic paints. Depending on the surface, that you plan on painting, the method for thinning your acrylic paints will vary quite a bit. In this article, I will teach you how to thin acrylic paint properly for every type of project.

Acrylic paints can be thinned with water or acrylic medium. Water thins the paint down and breaks down the binder in the acrylic paint resulting in diluted paint with less opacity. Acrylic paint will stop being opaque when it has been diluted by more than 30%. The acrylic medium will thin down the paint without diluting it.

As you can see, thinning acrylic paint is slightly more complicated than just adding some water and applying the paint.

Depending on the surface, that you want to paint, and the effect, that you want to go for, the way you thin down the acrylic paint changes drastically.

So in the following article, I will cover how to paint different materials as well as how to dilute the acrylic paint properly for every kind of project.

Can You Thin Acrylic Paints With Water?

As I mentioned above, acrylic paints are diluted by thinning them with water which can lead to unexpected outcomes and problems along the way. Some problems include bad coverage of the paint or changing the color of the paint when diluting it. This raises the question if it is even a good idea to thin acrylic paints with water in the first place.

Acrylic paints can be thinned with water. The water will dilute the paint resulting in less opacity. This is not a problem when just adding a little bit of water but when acrylic paint is diluted by more than 30 % then it will start becoming less opaque. Also the paint will lose its vibrant colors the more water is added.

Using water to thin acrylic paint is entirely possible and you can use water for thinning as long as you know the drawbacks and as long as you know what to watch out for.

I personally use water for thinning acrylic pain 99% of the time because it is convenient and it works great if you know what you are doing.

Don´t Dilute Acrylic Paint by More Than 30% with Water

When you still want your acrylic paint to be opaque, then you should not add more than 30% water to the paint.

Usually, you won´t need to add more than 10% of water to dilute the paint enough in order to apply them smoothly.

But depending on the kind of acrylic paint, that you are using, this number can vary slightly. Some acrylic paints are thicker than others and some high-quality acrylic paints have more color pigments in them which means, that you can add more water before diluting them too much.

Dilute Acrylic Paint by More Than 50% for a Wash

A wash is basically an application of highly diluted paint to slightly color the underlying material or painting.

I like to use washes to color natural wood without covering the natural grain or to add an overlaying color to a painting of mine.

Washes can have really awesome looking effects if used correctly. I always recommend testing the wash on a spare piece or in a corner of the painting before committing to it.

When you dilute acrylic paint with water by more than 50% then it won’t be opaque anymore so it can be used for washes or for adding effects to your project.

Adding Water to Achieve Different Artistic Looks

Depending on how much water you add to your acrylic paint the paint will actually dry differently giving the outcome a unique artistic look.

If you add more water, then the outcome will have a watercolor look to it and by adding only small amounts of water the outcome will have a guache feel to it.

You can even make the paint look like oil by adding a lot of acrylic medium and a little bit of water to the acrylic paint.

Just go ahead and try different mixtures and who knows, maybe you will find a really cool effect mixture or a way to make your acrylic paint look like Marmor once it’s dry.

Can You Thin Acrylic Paints With Rubbing Alcohol?

There are a lot of different acrylic paints out there. Some are water-based and others are latex or oil-based. And not every kind of acrylic paint can be thinned by using water. When I first heard about thinning acrylic paints with rubbing alcohol or mineral spirits I simply put it aside as a bad idea or a beginner’s mistake but there are situations where it actually makes sense.

You can thin acrylic paints with rubbing alcohol or mineral spirits if the acrylic paint is not water-based. In fact, it is the only way, aside from special acrylic thinning medium, to thin non-water-based acrylic paints. Non-water-based acrylic paints can be identified by their strong odor or by reading the information on the package.

This may come as a surprise to you, it did to me, but acrylic paint is not always water-based. Most of the acrylic paints, that you can buy in the craft store or in the hardware store are water-based but you can get special acrylic paint for outdoor use, for example, that is oil-based.

These acrylic paints can not be thinned by using regular water but instead have to be thinned by using either rubbing alcohol or, the option that I would recommend, using mineral spirits.

You can identify if your acrylic paints are water-based or oil-based by their odor. Oil-based paints have a very strong odor to them while regular water-based acrylic paints almost don´t smell at all.

You can also read the package if you are unsure.

Do You Wet Your Brush When Using Acrylic Paint?

This is a question, that I get a lot. It seems to be an old artist trick to make sure, that the acrylic paints can be applied smoothly. I personally never heard of it until I started this website and people started asking me if it is a good idea to make the brush wet when using acrylic paint. So I tried it and here is what I discovered.

You don´t have to wet your brush when using acrylic paint but using a wet brush to apply acrylic paint can be a nice trick to control the application of the paint a little better. By using a wet brush to apply the paint instead of thinning the paint with water it is easier to control how thin or thick to apply the paint.

When I first tried to apply acrylic paint with a wet brush instead of thinning the paint with water before applying it I was kind of skeptical. I used to think, that the best way to apply acrylic paint is to thin it before applying it. And I still do but only in some situations.

Generally, when you want to paint a big surface it is better to thin the paint before applying it because the wet brush method is not really good for applying a lot of paint at once.

However, if you want to paint a very intricate design or if you want to paint very detailed then the wet brush method is really the best choice.