thinning acrylic paint

How to Thin Acrylic Paint (Step By Step)

If your acrylic paint is too thick to work on, we have compiled a list of 100% risk-free step-by-step guide on how to thin acrylic paint for those artists who will not settle for anything less than a successful thinning operation.

In this guide, we explore the three thinning methods that are all effective, safe, and pocket-friendly.

We cover not only the basics behind the process but also of the more advanced steps so you can thin like other professionals.

Even if it’s your first time, you can use any of these methods and still achieve the effect you desire.

Read Also: How to Thin Oil Based Paints for Spray Gun

How to Thin Acrylic Paint [The Water Method]

How to Thin Acrylic Paint

The things You Need

  • Palette
  • Plastic container
  • Acrylic brush
  • Paper towel
  • Spare canvas or a surface
  • Clean water

This method is one of the most effective and less expensive thinning methods that is doable within a twinkle of an eye. It’s so simple almost anybody can do it.

However, without the proper knowledge, it can be challenging to get an excellent shade and viscosity needed for your art.

So, here is a couple of steps on how to thin acrylic paint with water without the polymer losing its binding properties, resulting in the dispersion of the pigment.

Use Higher-quality professional-grade acrylic paints

It’s better to spend more money on higher-quality grade paints than buying cheap lower-quality student-grade paint.

Professional-grade acrylics are the best bet when thinning with water.

It starts with a higher pigment-to-binder ratio. For this reason, you can add a lot of water to the paint to achieve different effects, without it breaking up into smaller specks of pigment as it dries.

Read Also: How to Thin Latex Paints for HVLP

 Put the Paint on a Palette

Remember, acrylic paints are fast-drying. Therefore using too much of it from the tube might result in an expensive waste.

That said, it’s smart to start working with a smaller quantity – adding more only when needed.

Start the Thinning Process

First and foremost, fetch clean water in a mini-sized container and keep it next to the palette.

When thinning the paint on the palette, gently dip your paintbrush into the clean water. Then, mix it all together.

Failure to mix thoroughly will result in clumping or uneven color.

WARNING! Too much moisture will decrease the overall quality of your art, leading to drips or peeling of the paint. One the other hand, too little may not get the effect you want.

Check the Consistency with a Palette knife.

When thinning, the thickness of the paint starts to change. Hence, you’ll need to keep track of the viscosity, using a palette knife to spread the paint onto the spare piece after each add-up.

If you are satisfied with the result, congratulation, you’ve successfully thinned the acrylic paint.

On the contrary, you should repeat steps 3 and 4 if you’ve not yet gotten your ideal result.

Expert Tips:

TIP 1# Blot your brushes regularly

Use a paper towel for blotting brushes after rinsing the brushes.

There might be some trapped moisture in the brittle, hence using the brush without blotting them could thin the paint – unintentionally.

TIP 2# Revitalizing Hardened Acrylic Paint

You can revive thickened paints if it is somewhat malleable.

Firstly, have a firm grip on the palette knife before attempting this process. Then, use grinding motions to remove the hardened paint.

However, if the paint has hardened completely, all hope is lost!

Read Also: How Much Does It Cost To Paint Kitchen Cabinets?

Are There Other Methods of Thinning Acrylic Paints?

thinning acrylic paint

Water is just the primary thinner. Aside from water, there are other preferable options by professionals like the use of chemical thinners or thinning mediums – although, they’re pricier alternatives.

Let’s take a look at them in full.

The Acrylic Medium Method

Most expert painters prefer using an acrylic medium to thin acrylic paint instead of water because the medium does not decrease or wreak the bonding strength – due to the acrylic binder in it.

Additionally, it allows the paint to sit on top of the surface, maintaining its glossy appearance.

Furthermore, there are various types of thinning mediums with distinctive benefits.

Below is a list of acrylic medium to choose from for any effect:

  • Gloss Medium: If you want to paint thin, yet in brilliant glaze, use the gloss mediums. It enhances the natural sheen and luminosity of the acrylic paint.
  • Matte Medium is excellent for a subtle, non-reflective finish. Additionally, you can mix gloss and matte mediums together (equally) to achieve a semi-gloss effect.
  • Glazing Medium gives the same effect as a gloss medium. Although the oil-based models are not suitable with acrylics paints.
  • Gel Medium is a white paste-like gel that improves the adhesive properties of the paint. Also, it is ideal for impasto techniques and collage.
  • Modeling Paste is like gel medium, but thicker and harder. Thus, it’s excellent for collage art.
  • Texture Gels adds a texture effect to any artwork.
  • Retarding Medium is good in slowing down the dry time of acrylic paint. Thus, making time your friend when thinning or mixing colors.
  • Flow Improver thins the paint without compromising the finish or reducing color strength.

Read Also: Latex vs Acrylic Paint


Repeat the same steps on how to thin acrylic paint with water above, but this time, use a thinning medium in place of the water.

The Spirits and Paint-Thinners Method

Thousands of professional painters and artists are using this homemade remedy to reach their desired result.

You can use chemical thinners such as rubbing alcohol and acetone to manipulate the paint in getting the effect you want. Besides, they are accessible in the local art store.


The same thinning rules applied to Spirits and Paint-thinners when thinning your paint.

Read Also: How to Paint Wood Texture with Acrylic Paint

How do you thin out acrylic paint?

The best way to thin acrylic paint with water is to mix 30-50% of the water with the paint (1:2 ratio). 30% of water or less to acrylic paint thins it lightly and allows you to coat a surface. Add 30% water when your work with pre-primed surfaces.

Can you use rubbing alcohol to thin acrylic paint?

So if you are looking to use rubbing alcohol to thin your paint, opt for lower concentrations (30-70%) or dilute the alcohol with water before mixing with your acrylic paint. As for acetone, the same general idea applies.

Can you use water to thin out acrylic paint?

Acrylic paints can be thinned by adding water, a pouring medium, or using an acrylic binder.

How do you thin heavy acrylic paint?

The Heavy Body Acrylics can be thinned very effectively with water, but since the Fluids start at a lower viscosity, less water is needed. Remember: the more water added to the acrylics, the greater the subsequent shrinking of the paint layer.

Can I use acetone to thin paint?

ByBrittney. A nail polish remover made from acetone can be used to thin paint or clean up spills and spatters. The solvent acetone is a powerful one for both oil-based and latex-based paints, and it can be used to remove paint from a wide variety of surfaces that have not been cured.

What is an acrylic binder?

An acrylic binder is a multi-purpose product, often used to optimize the coating characteristics of a metal’s surface for the purpose of protecting the metal against corrosion. Acrylic binders can be used as a glue, paint or spray. However, its primary purpose is to improve adherence of pigments in paint.

Can you mix water paint with acrylic paint?

By mixing acrylic with watercolor, you can create paint with very unique qualities of color and opacity, that can be adjusted based on the ratio of the paint types and water. All you have to do is set up a palette with several colors of watercolor, and using a palette knife, mix them with a dab of acrylic.

What do you add to acrylic paint to make it flow?

A ratio of one part paint to three parts water should be enough to break down the acrylic binder so that the paint acts like watercolor. Also use fluid acrylics for glazing over another color, for creating drips (an eye dropper works well for this), for bleeding colors into each other, and for pouring.

How do you dilute dried acrylic paint?

You can fix dried out acrylic paint by mixing them with some warm water. Only a small amount should be added at a time to avoid thinning down the paint too much. This only works if the paint has been sealed inside the container, so that the paint was not exposed to fresh air when it dried out.

Can I use alcohol to thin paint?

Isopropyl (rubbing alcohol) can thin water-based acrylic paint. It is recommended that you dilute paint with up to 20% alcohol. Alcohol accelerates drying and can result in uneven application, which is why it should not be used.


As you can see, there are different ways how to thin acrylic paint that you can use.

Water thinner might be a cost-effective solution. However, it’s not advisable for beginners because a slight mistake can ruin your paint.

I would recommend mixing with a thinning medium, spirits, or paint-thinners because you gain more control when thinning your paint. More importantly, they prevent paint from drying out too quickly.

CAUTION! You should use your brush to apply the agent little by little until you get the desired effect. And, always adhere to the manufacturer’s directions for the best results.