why is my acrylic paint watery

Why Is My Acrylic Paint Watery?

If you’ve ever noticed that your acrylic paint is watery and does not provide the typical thick, opaque coverage of which it’s known, you aren’t alone. 

Many artists have experienced this frustrating issue with their acrylic paints, leaving them wondering why such a seemingly simple media can quickly become so complex.

In this blog post, I will dig deeper into what could be causing this common problem and provide solutions for returning to painting with reliable results. 

With patience and careful attention to detail in application techniques, you can find the balance between a paint consistency that flows freely yet still holds its shape when dry. 

Let’s dive right in. 

Why Is My Acrylic Paint  Watery

Your acrylic paint is watery because you’ve combined too much water with the paint, which dilutes its viscosity and makes it thinner. Another cause could be that you’ve exposed the paint to temperatures outside of its ideal range. If you’ve left your paint open to the air for an extended period of time, the water in it can evaporate and cause a thinning effect. 

7 Major Reasons Your Acrylic Paint is Watery

1. The paint has stayed in the house or on the store shelves for Long

If your paint has been sitting around for a while, it may have gone bad. Bad acrylic paint will become watery and lose its pigment.

What’s more, acrylic paints are a type of water-based pigment, which means they typically need to be used once opened and should not stay open for too long. 

Water-based latex paints, for instance, last 10 years before opening, but as soon as it’s open, they can go up to 2 years max.

Microbes are often introduced into the paints via brushes, unclean palette knives, or keeping acrylic paint after mixing it with water.

Also Read: Can You Mix Acrylic Paint With Wall Paint?

2. Your acrylic paint might be of Low quality

Why Is My Acrylic Paint Watery?

Acrylic paints come in various qualities and grades, from student grades to professional grades.

If you are using low-quality paint, it will likely be more watery and difficult to work with than a higher-quality option. 

Student-grade paints have less viscosity and opaqueness than artist-grade paints due to the higher filler.

You may notice this while painting, especially with cheaper student paint ranges. To address this, you can purchase higher-quality student paints or switch to artist paints.

3. The paint is naturally made of watery

Is acrylic paint water based? Some brands of acrylic paints are purposely fluid acrylics. They have more water than other types, making them thinner and easier to blend and layer. 

While this can have advantages in certain types of painting and art, such as watercolor-style work, it can make it difficult to control your brushwork if you’re working on a project with more detailed lines and shapes. 

4. Too Cold temperatures

Acrylic paints are not meant to be used in cold conditions – the colder it is, the thicker and more difficult to use they become. 

Does acrylic paint freeze? Well, if your acrylic paint has been exposed to cold temperatures for too long, it can solidify in the tube or bottle, making it extremely hard and almost impossible to work with. 

5. Manufacturing defects

Sometimes, a manufacturing defect can cause your acrylic paint to be overly watery.

This is usually due to an error in the production process, where too much water or not enough pigment has been added, making it difficult to use.

Read more: Why was the acrylic tank manufacturing closed?  

6. Over thinning

When you’re working with acrylic paint, it’s important to remember that a little goes a long way – if you add too much water to your paint, it can become overly thin and difficult to work with. 

To avoid this, always use a small amount of water when mixing your paint and work in thin layers. 

7. Exposure to air

Over time, air exposure can cause acrylic paints to dry out and become watery due to evaporation, similar to how paint left open for too long will dry out. 

The air starts to evaporate the liquids out of it, leaving it increasingly thin and watery.

If your acrylic paint has been stored in the house or on store shelves for a while, it may have dried out and become too watery to use, probably because of air exposure.  

Watery Acrylic Paint Problems

Watery acrylic paint can cause various problems for artists, ranging from poor coverage and paint color intensity to difficulty in achieving the desired effect. 

Acrylic Paint Too Thin

why is my acrylic paint watery

It is also possible for acrylic paints to be too thin and watery if you add an excessive amount of water.

This will result in very weak colors that are difficult to cover whatever surface you are painting on.

Additionally, the paint’s low viscosity means it doesn’t adhere well to surfaces, leading to a weak adherence that can easily be wiped off.

Paint Running

Watery acrylic paint can also tend to run when it is applied to a surface.

This occurs because the water in the paint causes the molecules of pigment to separate from each other.

As a result, the particles start to move down whatever surface you are painting, creating streaks and blotches which ruin your artwork.


Bleeding is when the paint spreads out beyond the area you intended it to cover, leaving behind unsightly outlines of color next to each other.

This issue is often caused by using too much water in the mixture or layer thickness that is not consistent. 

Ghosting on Your Paper or Canvas

Ghosting occurs when the paint leaves a faint layer of color that looks like a ghostly shadow over the areas that were previously painted.

This can be caused by using too much water or having inadequate adhesion between your substrate and the paint layers.

To fix this issue, use a higher quality acrylic paint that has better adhesion and apply the layers in thicker coats.

Pale Outlook

Watery acrylic paint can often result in a very pale and washed-out look. This is because the consistency of the paint is so thin that it does not completely cover whatever surface you are trying to paint.

As a result, you get an uneven coverage that prevents color saturation or vibrancy.

Variation in Texture

Watery acrylic paint often has a mottled appearance due to the variation in consistency from thicker to thinner areas.

This means that when you apply the paint onto a canvas or other surface, there will be different textures created based on how much water you’ve added to the paint.

The thicker areas often create a raised texture, while the thinner areas may appear uneven or patchy.

How to Make Watery Acrylic Paint Thicker

The following methods can be used to fix watery acrylic paint. Learn how to thicken your acrylic paint to use it for a variety of painting techniques, such as applying thicker layers or making textures: 

Use a Gel Medium

Gel medium is a great way of thickening acrylic paint and making it more textured, as it adds body to the paint to retain brushstrokes and peaks.

It can also be used to add transparency or glossiness to the color, depending on the type of acrylic gel medium used.

Mix a small amount of the gel medium with the paint on a palette before applying it to your surface.

Read Also: How to Make Acrylic Paint More Opaque

Mix in Some Cornstarch

Cornstarch is an inexpensive and effective thickening medium for acrylic paints.

Simply mix in a little bit until you achieve the desired consistency. Be sure to stir thoroughly as you go.

Try Using Flour

A flour paste can be used to thicken watery acrylic paint as well. Mix a few tablespoons of all-purpose flour with some cold water until it forms a smooth paste, then stir this thickening paste into the paint until you have reached the desired consistency.

Use a Modeling Paste

Modeling paste is a thick, heavy-bodied liquid that contains acrylic polymer with marble dust and other additives.

You can mix it in with your watery paint to create a thicker consistency.

Use a Thickening Agent

How to Make Watery Acrylic Paint Thicker

A variety of products are available for use as thickeners for acrylic paints. These products usually come in a powdered form and are designed to be mixed into the paint before use.

Add More Paint

This may seem obvious, but adding additional coats of paint can help thicken up watery acrylics without making them too thick or heavy.

Just be sure to allow each coat to dry thoroughly before applying the next one. 

Read also: Is floetrol a pouring medium?

Comparing Different DIY Methods To Thicken Watery Paint

Joint Compound DIY Thickener

Joint compound is a popular DIY thickener for watery paint because it is affordable and easily available at most hardware stores.

It is a gypsum-based product commonly used for drywall finishing. When added to paint, it creates a smooth, thick consistency that can help hide imperfections and create texture. 

However, joint compound is not suitable for all types of paint, and it can be difficult to get the desired consistency. 

It also dries quickly, which means that you need to work fast to achieve the desired result.

Plus, joint compounds may affect the drying time and overall quality of the paint.

Corn-Starch or Flour DIY Thickener:

Corn starch or flour is a common household ingredient used to thicken watery paint.

These DIY thickening agents are cheap and easy to use. However, they are not recommended for all types of paint. 

When added to paint, they tend to create a lumpy texture and can be difficult to mix thoroughly.

They also tend to dry out quickly, meaning you need to work fast to achieve the desired consistency.

Moreover, corn-starch or flour may affect the drying time and adhesion of the paint.

PVA or Talcum Powder DIY Acrylic Thickener:

PVA glue and talcum powder are also popular DIY thickeners for watery paint. PVA glue is commonly used in woodworking and can be easily found at most hardware stores.

When added to paint, it creates a smooth, thick consistency that is easy to work with. 

Talcum powder, on the other hand, is a fine powder commonly used in cosmetics and personal care products.

When added to paint, it creates a smooth, creamy consistency that can help to cover imperfections and create texture. 

However, PVA glue and talcum powder can affect the color and quality of the paint, and they may also affect the drying time and adhesion of the paint. 

PVA glue can be difficult to mix thoroughly, and talcum powder may leave a residue that can be difficult to remove.

Advantages of Using Thick Acrylic Paint

Using thick acrylic paint can offer several advantages for artists, including:

Bold, expressive textures

Advantages of Using Thick Acrylic Paint

Thick acrylic paints are great for creating dynamic and eye-catching compositions.

The thick consistency of the paint allows artists to create heavily textured pieces with various implements such as brushes, knives, or even fingers.

It retains its shape and texture as the paint dries, making it an ideal choice for more tactile compositions.


Acrylic paints can be used in various ways, from painting on canvas or paper to creating mixed media pieces with other materials, such as fabrics or pastels.

They are also very flexible regarding the final finish – they can be left matte or glossy, depending on the desired outcome.

Easy blending and mixing

Thick acrylic paints can be easily blended and mixed to create an impressive array of colors and shades.

This allows artists to find various color combinations that will suit their needs.

Better coverage

Due to the high pigment content, thick acrylic paints provide excellent coverage with fewer coats.

This makes it much easier for artists to achieve a consistent and even finish in their work.

Besides, thick textured paint lets you build visible layers and textures on your canvas without the need for any paint thickener.

Heavy-bodied acrylics, such as these, are perfect for impasto painting styles.

Faster drying time

Acrylic paints dry quickly, making them ideal for artists who need to work quickly or don’t have the luxury of waiting long periods of time between layers.

This also makes it easier to layer the paint without worrying about it becoming too clumpy or difficult to blend. If you find trouble with clumpy paint, here is how to fix lumpy acrylic paint.

Great color intensity

Due to the high pigment content, acrylic paints have an intense color quality that won’t fade or dull over time.

This makes them a great choice for works of art intended to last. The vividness of the colors also makes them ideal for creating vibrant and striking pieces.

Prevention Tips To Avoid Watery Paint

Proper storage and handling– Acrylic paint can become watery if it is not handled and stored properly.

Make sure to keep your paint in a cool, dry place away from direct sunlight, and tightly seal the container after each use.

Additionally, try to avoid exposing your paint to extreme temperatures or humidity, which can cause the paint to separate or thin out.

Careful measuring and mixing– When preparing your paint, be sure to carefully measure out the correct amount of water or medium to avoid over-thinning.

Use a measuring cup or dropper to add the correct amount of water or medium, and mix the paint thoroughly to ensure that the pigment is evenly distributed.

Using quality paints and mediums-Investing in high-quality acrylic paints and mediums can help to prevent issues with watery paint.

Cheaper paints or mediums may not have the same consistency or pigment quality, leading to problems with coverage, adhesion, and durability.

Avoiding over-thinning- As mentioned, over-thinning is one of the main causes of watery acrylic paint.

To avoid this issue, try to add water or any paint thinner in small increments, mixing the paint thoroughly after each addition.

Be sure to test the paint’s consistency frequently to ensure that it is not becoming too thin.

Using airtight containers– After use, transfer any unused paint to airtight containers.

This can help prevent evaporation and the paint from becoming too watery. Also, avoid leaving paint containers open for too long.

Storing paint containers upside down– When storing your paint, try to store the container upside down.

This can help prevent air from getting trapped in the container, causing the paint to separate or dry out.


Can I thicken my acrylic paint?

Yes, you can thicken your acrylic paint using a variety of methods. You can add a thickening acrylic mediums such as gesso, thickening gel medium or mod podge to the paint to make it thicker. You can also use an additive like cornstarch, flour or baking soda to thicken the acrylic paint.

Why is my acrylic paint runny?

Acrylic paint can become runny if it has been stored for too long or mixed with too much water. If you’re using store-bought acrylic paint, it may have been watered down by the manufacturer to increase its shelf life. You can also thin the paint by adding a lot of water while mixing, which will make it runny.

How can I thicken acrylic paint without a medium?

You can thicken acrylic paint without a medium by adding an additive such as cornstarch, flour, or baking soda. Simply mix the desired amount of your chosen additive with the paint until it reaches your desired thickness.

Does flour thicken acrylic paint?

Yes, you can add a small amount of flour to your acrylic paint in order to thicken it. Remember that if you add too much flour, you may end up making the paint gummy, so it is best to add a small amount at a time until desired consistency is achieved. 

Does mixing water in the paint make the paint thicker?

No, adding water to your acrylic paints will thin them out and make them runnier. If you want to thicken your paint, use an acrylic medium such as gesso, ArtResin, Cell-Tac, or Clear Tar Gel. You can also add small amounts of white glue to the mix for temporary thickening.

What can I do if my paint is still watery after adding thickening agents?

If your paint is still too watery after adding a thickening agent, you may need to add more or mix it for a longer period of time. You can also try adding an acrylic gel medium to the paint, which will help it form a thicker consistency. Alternatively, you may need to start with new paints and fresh additives.

Can watery acrylic paint be mixed with oil paint?

No, acrylic paints should not be mixed with oil paint. Acrylic paint is water-based and dries quickly, while oil paint is oil-based and dries slowly. Mixing them together can cause the paint to separate and not adhere properly to the surface, resulting in cracking or peeling of the paint. Mixing the two types of paint can create an unstable and unpredictable medium, which may lead to discoloration or other issues.


Watery acrylic paint is never ideal when painting, but with a few easy tips and tricks, you can bring them back to life.

Experimentation is key in learning what works best for your paints, and trial-and-error is the fastest way to understand the products you’re using on your canvas.

Make sure to keep all brushes and painting surfaces clean before and after use, and don’t forget to add extender medium or water sparingly if needed.

With enough practice, any blip with watery acrylic paint can be resolved in no time. 

Now that you know more about why paints become too thin, why not take the leap of faith today and get creative.

Put these techniques into practice and resolve the reason your acrylic paint is watery.


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