TL;DR:
This guide explains how to thicken acrylic paint without damaging color, adhesion, or long-term durability. You’ll learn which professional methods work best, which shortcuts and home hacks to avoid, and how to get controlled texture that behaves the way acrylic paint should. Here are some highlights this blog covers:
- Why acrylic gels and modeling pastes are the safest media to thicken acrylic paint
- How proper ratios help maintain rich pigments, flexibility, and adhesion
- When textured gels make sense for added dimension and surface interest
- Why DIY thickeners like cornstarch or baking soda can weaken acrylic paint
- When to choose heavy body acrylic paint instead of thickening it yourself
Acrylic paint flows smoothly, dries quickly, and is well-suited to a variety of media and surfaces. That said, paint straight from the tube might not cut it for you, depending on how you’re using it.
As we explained in our guide on how to thin acrylic paint, controlling acrylics is all about balance. This is true for both thinning and thickening acrylic paint. Of course, each process is a little different.
If you’re wondering how to thicken acrylic paint without dulling the color or weakening its durability, the answer comes down to using the right materials in the right way. Here’s what you should know.
What is the Best Way to Thicken Acrylic Paint?
The most dependable way to make your acrylic paint more viscous is to use specially formulated acrylic gels or modeling pastes that have been created for use with acrylic paint.
Why? It all comes down to chemistry. We won’t bore you with the details, but dedicated acrylic gels and modeling pastes contain acrylic binder, which is essentially the key ingredient that holds pigment together and helps paint adhere well to a surface once it dries.
Sources like wikiHow explain that acrylic thickening gels allow paint to “hold its structure,” making them ideal for impasto techniques. In case you’re unaware, impasto is just a way of applying paint thickly, so brush or knife marks remain visible once the paint dries.
If you’re going to use this technique, you’re going to need thicker paint.
Tips for How to Thicken Acrylic Paint
When using a medium to thicken acrylic paint, be sure to:
- Start with a small amount
- Keep the ratio under one part gel to four parts paint
- Mix with a palette knife for even consistency
Because acrylic gels, such as #209 Super Gel, share the same chemistry as acrylic paint, they maintain flexibility as the paint dries, which reduces the risk of cracking. This is extremely important if you’re not going for a crackle-finish that looks like dried yogurt or drought-scorched desert land!
Consider Textured Gels for Adding Surface Interest
Looking for both more thickness AND more texture?
Textured acrylic gels are another professional option you may wish to consider. Products like #250 Coarse Lava Gel, have fine particles added into them that add some grit or dimension while remaining fully compatible with acrylic paint.
Plus, unlike household additives like sand, textured gels help your acrylic paint maintain its adhesion and durability.
Consider Heavy Body Acrylic Paint
You can buy thick acrylic paint (called “heavy body”) instead of regular acrylic paint. If you require a lot of texture for a majority of your work, then starting with this type of paint might be a good option.
Why DIY Thickening Methods Are Not Recommended
You might see suggestions online for “hacks” on how to thicken paint using things like cornstarch, flour, baking soda, sand, or similar items that you might have lying around the house.
Most sources, however, including this guide from RK-Chem, note that these additives can affect durability and finish. Therefore, at Nova Color, we recommend against using them, especially for fine art.
Household thickeners are just not chemically compatible with acrylic binders. Therefore, when used, they:
- Weaken adhesion
- Decrease paint flexibility
- Create chalky or uneven finishes
- Increase cracking or flaking over time
Get More Tips on Using Acrylic Paint
Check out our Acrylic Painting for Beginners guide for additional information!
Looking for some of the best acrylic paint on the market to complete your next project? We invite you to shop our high-quality acrylic paint now.