How to Thicken Acrylic Paint

There are benefits to thin acrylic paint, somewhat similar to watercolor, but you can also thicken acrylic paint. Thick acrylic paints are easy to use for acrylic painting. You can get the color and texture you want. Thickened paint has a consistency that lends itself well to painting texture. It is often used in printmaking and preliminary drawing with charcoal or pastels. Acrylic paints are fantastic mediums because of their many benefits, but sometimes the paint can be too thin for your needs. So if you want to know how to thicken acrylic paint, this post is for you!

We have the solution to this problem. How to thicken acrylic paint is a question often asked by many artists. Acrylic paint is water-based, but it may become too runny or thin at times. There are various ways to make it thicker in such cases, but natural methods work just fine. This article will show you how to thicken or increase the viscosity of your acrylic paint.

What is Acrylic Paint

mixing color for painting

Countless artists worldwide work with acrylic paints because of their affordability and convenience. There are three components of acrylics: a pigmented acrylic polymer emulsion, a vehicle, and a suspended pigment. It is the vehicle that carries the pigment and binder. Acrylic paint uses water as the vehicle. We know acrylic paint as a gooey, water-soluble substance of pigmented emulsion. The water absorbs or evaporates from the acrylic paint, which causes the resin particles to fuse together when it dries. Thus, the paint becomes waterproof and strong. You can spot the binder in separated paint by the clear liquid substance that erupts from the tube before the colored pigments.

Additives like anti-foaming agents and surfactants may also be found in paints. Manufacturers have their own formulas and standards in this area. Even the amount of pigment varies from manufacturer to manufacturer. In cheaper paints, fillers and dyes are used instead of pigments since they are less expensive.

Acrylics usually have a consistency of a thick, spreading liquid. Since they are creamy, they can be applied easily and quickly dry. Fluid acrylics flow easily and are thin inconsistency. Paint can be splattered or dribbled on them and sprayed or stained with them. Acrylic paints typically have a buttery, thick texture. The paint adds texture to paintings by holding peaks easily. The use of thick, textured paint can create layers and textures that can be visible on your canvas without adding additional medium. Acrylic paints with a heavy body, such as these, are excellent for impasto techniques.

Acrylic paints are popular among artists because they are cost-effective and easy to work with. These products are water-soluble, have a mild odor, and are non-flammable and fumeless. Acrylic paint can be easily removed from brushes and surfaces without thinner. You can thin acrylic paints with water if you want an effect similar to watercolor. As an alternative to acrylic paint, the acrylic medium can be added to change any aspect of the paint, from the finish and texture to drying time and thickness.

Thick Acrylic Paint: Why Do You Need It

Let’s talk about why you might want to thicken your acrylic paint before we begin to look at how to thicken acrylic paint. Some artists use thickened acrylic paint to add depth and texture to their work, just like they use thinned acrylic paint for washes. Impasto is a painting technique in which brushstrokes and paint brush strokes can be seen on the final product because the paint is applied thickly.

The impasto technique produces paintings that look like they are emerging from the canvas. Van Gogh and Rembrandt were among the many famous artists that used impasto techniques in some of their most notable works. The outcome of an impasto painting shows a visual record of the painting process as it allows the completed painting to be expressive. This technique can also mix the paint directly on a canvas instead of on a palette. Many artists enjoy experimenting with the impasto technique because it provides a way to play around with different textures and depths in landscapes, portraits, and still-life paintings.

Buying a cheaper acrylic paint brand may not be appealing in terms of its thickness, or you may have purchased the wrong acrylic paint thickness by not reading the label correctly. Some paints can break down if they’re a little past their shelf life or if they haven’t been stored properly. Whatever your reasons for thickening acrylics, we provide a variety of methods below.

How to Thicken Acrylic Paint: Best Ways

In this section, we will demonstrate how to make acrylics thicker. Acrylics are available in a variety of consistencies. There are acrylic inks, fluid acrylics, soft body acrylics, and acrylic gouache. 

Thicken Acrylic Paint Using Gel

Pretty much any gel will make these paints thicker. I’ll cover that more later, but I’d like to focus on the heavy body acrylics for now. That’s because they’re the most common types of acrylics that you find in stores and then artists use. 

The acrylic gel is basically the same thickness as heavy body acrylic paint. So when you add regular gel to heavy body acrylics, you’re just making it more transparent. It really doesn’t do anything to make it thicker. Fortunately, they make thicker acrylic gels. 

acrylic gel for Thicken Paint
Photo Credit: Chris Breier

On the left is the regular gloss gel and then on the right is the Liquitex super heavy gel. In this close-up, you can see that the super heavy gel on the right is definitely thicker. It has crisper edges, and it even looks whiter. I think that’s because it has a higher solid content. The white appearance of acrylic gel is temporary.

how to thicken acrylic paint
Photo Credit: Chris Breier

As it dries, it begins to clarify. This actually makes your colors a little bit lighter when they’re wet, and it explains why acrylic paint darkens as it dries.

Thicken Acrylic Paint Using Modeling paste

Modeling paste using to thicken acrylic paint
Photo Credit: Chris Breier

Modeling paste is another option; it’s basically acrylic gel mixed with marble dust. The only issue is that it makes the colors lighter, as you can see here. If you don’t like pastel colors, you can use modeling paste to texture your canvas.

how to thicken acrylic paint
Photo Credit: Chris Breier

let it dry, and then paint over the top of it. In this still-life painting, artists used super heavy gel to make the heavy body acrylics thicker. You can see that it makes it glossier, and the brushstrokes and palette knife marks show up more. You can add as much gel to the paint as you like just keep in mind that if you add a lot of it, it will make it more transparent.

 acrylic paint thicken materials
Photo Credit: Chris Breier

Another technique is to use thin acrylics for most of the painting and then add gel for the areas where you want to build texture. For example, here’s an old bottle of Liquitex soft body acrylics. Straight from the tube, it goes on smoothly without showing the brush marks. You can add regular gel to make it thick enough to create some impasto with the palette knife. Use thicker gels to create extra thick and pronounced textures. The gels may make the colors mark transparent, but it’s not as noticeable since you’re thickly applying the paint. This is much more economical than buying the same colors in different lines of acrylics. 

Keep in Mind

  • Soft Body Acrylics
blue color acrylic painting
Photo Credit: Chris Breier

The soft body cobalt blue hue has a thin consistency and dries to a satin finish. Soft body acrylics are suitable for creating smooth and flat areas of smooth color.

  • Mixed With Gloss Gel
gloss gel mixed for thicken paint
Photo Credit: Chris Breier

Adding gloss gel to the soft body acrylic paint makes it thicker, glossier, and more transparent. Regular gloss gel has the consistency of heavy body acrylics. It retains peaks and bristle marks.

  • Mixed With Super Heavy Gloss Gel
Super Heavy Gloss Gel mixed for thicken paint
Photo Credit: Chris Breier

The super-heavy gel is thicker than heavy body acrylics. Adding it to soft body acrylics will allow the paint to hold tall peaks and other palette knife textures. While it does make the paint more transparent, it’s not as noticeable in thicker layers.

How to Make Acrylic Paint Thicker at Home

how to thicken acrylic paint
Photo Credit: Chris Breier

Suppose you’re looking for less expensive do-it-yourself solutions. So, we will test joint compound and flour for thickening acrylics. 

Thicken Acrylic Paint Using Joint Compound

Acrylic Flour to thicken paint
Photo Credit: Chris Breier

First up is the joint compound. It’s normally used to seal the joints between sheets of drywall. It’s relatively cheap, and it’s available from home improvement centers. The joint compound is light gray in color.

mixing for thicken paint
Photo Credit: Chris Breier

This is Van Dyck Brown in Golden’s fluid acrylics. The joint compound has a gritty feel when I mix it with a palette knife, but it does make the paint thicker. I also noticed that it lightens the color somewhat. We will compare the results with the white flour after it dries.

Thicken Acrylic Paint Using Flour

 acrylic flour
Photo Credit: Chris Breier

White flour is used to thicken the gravy, so it’s easy to understand why people want to add it to acrylic paint. I’ll use the same colors I use with the joint compound. I notice that it doesn’t have a gritty feel when I mix it with the palette knife. It also doesn’t lighten the color as much as the joint compound. 

thicken paint color
Photo Credit: Chris Breier

However, after working with it for a while, we noticed the mixture became sticky and kind of gummy. If you have ever made pizza dough, you know that flour becomes more stretchy as you work it. This is not the quality I’m looking for in a painting. It feels a little strange mixing a dry powder into acrylic paint. Acrylics dry rapidly, and adding a powder to them will make them dry even faster. 

Comparing the Durability of Different Methods

how to thicken acrylic paint
Photo Credit: Chris Breier

Here’s a comparison between the dry samples. The joint compound lightens the color much more than the flour and has some color variations. The flour also has a coarse or lumpy

appearance. Painted these samples on watercolor paper because it’s flexible, and want to test them to see if they’re prone to cracking

prepare color
Photo Credit: Chris Breier

So here’s the joint compound. Yeah, it already cracked. And see if you can bend this flour. That seems to be more. I just heard it snap. Yep the green cracked too – let’s try the flour. Yep, see that? So neither of these are really flexible and look at that large crack. 

how to thicken acrylic paint
Photo Credit: Chris Breier

I used palette paper to mix up the medium and it’s much thinner so I should be able to bend this to a greater extent and see if it cracks. I’m folding this pretty much in half. I don’t see anything. 

artist mixing color
Photo Credit: Chris Breier

Let’s try the thicker and that’s folded in half and it’s not cracking. It’s a very thick area and that’s flexing completely. 

Therefore, Adding joint compound or flour to acrylic paint may be acceptable when longevity is not a concern.

Credit: Chris Breier

The Problem With Paint Hacks

When it comes to painting, artists are willing to try nearly anything. Additionally, we tend to be cheap. To troubleshoot issues with our materials, we develop all kinds of ideas. Thickening acrylic is one of those ideas.

For a frugal artist, thickening products made from common household products may make sense. Flour and corn starch are two common options. It’s no wonder they’re great when you’re thickening a sauce, right?

There is no doubt that things like that may appear like an inventive paint hack, but we need to look at the long-term implications. Here, we are most concerned with the durability of the paint. The hacks listed here may work right now, but you want your painting to last as long as possible. If you add an unknown element, your paint’s archival qualities will be compromised.

Additionally, you should consider the workability of your paint using these non-traditional additives. There is a specific formula for artist paints, and part of that formula determines how well acrylics mix with water.

However, even when you’re thickening the paint, there is a chance that you will want to thin it occasionally or add a wash on top. In acrylics containing cornstarch or flour, adding water will create a slimy and unpleasant paste. In this case, a red paint hack may turn pink, and the hue could change immediately, or it could happen later.

Frequently Asked Questions

Can acrylic paint be thickened?

Acrylics can be thickened with specialized thickening gel without ruining your paint. This kind of gel is designed specifically for acrylic paint and should not affect the finish or color of your paint. The acrylic thickening gel can be purchased at arts and crafts or hardware stores.

Is there a way to thicken acrylic paint without cornstarch?

It only takes a little bit of joint compound to thoroughly mix with paint and wait for the mixture to form the desired consistency. Acrylic paint will easily blend with joint compounds. Talcum powder will work similarly. After adding water to create a paste, mix the acrylic paint with it once it reaches the appropriate thickness.

How do you fix watery acrylic paint?

The addition of a thickening gel can help thicken watery acrylic paint, but cornstarch and flour can also thicken it. Most acrylic paints only need a little bit of thickener to stop being so watery.

Can gesso be used to create texture?

One of gresso’s most remarkable properties is that it can add texture without any other materials. To begin, cover your painting surface with a layer of gesso before painting. Add another thicker layer of gesso after the first layer is dry. Gesso is given a classic, stucco-like appearance by using sponges.

Final Words

We hope this article has helped you to thicken your acrylic paint. You can apply any of these options to make your acrylic paint thicker than regular. As you can see, there are various ways to thicken acrylic paint. You can mix and match techniques to arrive at the best solution for your needs. Don’t be afraid to experiment. 

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