How to Fix Lumpy Acrylic Paint?

Straining the lumpy acrylic paint through a fine mesh strainer is probably the easiest way to fix lumpy acrylic paint. Apart from that, lumpy acrylic paint may be fixed by mixing water or a suitable paint medium as well. If the lumps are on paintings, then they can be removed using a tweezer. 

If you’ve found your acrylic paints to be lumpy or chunky and don’t know how to fix lumpy acrylic paint, this guide’s designed for you. 

Go through it, and you’ll end up learning a bunch of ways to remove lumps. And also how you can protect the paint from getting lumpy or chunky. 

Key Takeaways

  1. Fixing lumpy acrylic paint is a breeze if you use a fine mesh strainer, however, some paint might get wasted during the process.
  2. For the best consistency and good finish, use acrylic paint medium to remove the lumps. 
  3. The most common reason behind paint getting lumpy is bad storage, when the paint loses moisture, it becomes chunky and lumpy.

Here’s How You Fix Lumpy Acrylic Paint

There are a few effective methods to fix lumpy or chunky acrylic paint, in this section, we’ll be going through most of them. Let’s go!

Using a Strainer 

The easiest way to remove lumps or chunks from acrylic paint is probably by straining the paint with a mesh strainer. It won’t have to be a strainer designed for paints, pick any strainer. 

Before you empty the tube or container on the strainer, check the consistency of the paint. Is it very thick? Then it’d be hard to strain. In that case, you’ll have to add a few drops of water and then mix thoroughly. 

Sometimes only water might not work, in such situations, a paint thinner is the best option. 

After mixing well, when you get the required consistency, now you can strain it. Pick an air-sealed container to take the strained paint and set the strainer on the container opening. 

Put a little amount of paint on the strainer and let it strain slowly. You’ll see the lumps or chunks are left on the strainer while the paint is poured into the container. 

Palette Knife

Fixing the lumpy acrylic paint by using a high-quality palette knife is another easy way. All you require to do is, take the needed amount of paint and break these lumps using the knife. Just squeeze the lumps, they should break. 

If you find these lumps hard to squeeze, then a high-quality palette knife isn’t going to work. In this case, you’ll need a tweezer. And you’ll have to take out the lumps one by one. Yes, that’s going to be time-consuming if the paint is filled with lumps, but that’s worth it.

Using Water 

This is one of the most effective ways of getting rid of chunky and lumpy acrylic paint. However, you certainly need to be very careful when putting water to remove the lumps because excess water will make the paint very thin.

Here’s how you can remove lumps from acrylic paint using water:

  1. Squeeze out all the paint from the tube or empty the paint container. Use a plate or palette to keep the paint.
  2. Use a palette knife or the paint brush’s stick to stir the paint. If you’re using palette knives, try squeezing the lumps; that will give a better result. 
  3. Never pour water into paint using a mug, cup, bottle, or anything else. It’s wise to use a dropper. 
  4. Put certain drops of water into the paint and thoroughly mix it until you get a good consistency. If the paint feels very thick, add a little more water. 
  5. Keep mixing until you see the lumps or chunks disappearing and the paint consistency is good. Make sure not to add so much water that the paint becomes very thin. 
  6. After you’ve removed the lumps successfully, pour the paint inside an air-sealed container for proper storage. 

Using a Medium 

Though using a painting medium to treat lumpy acrylic paint costs you a little money, it yields the best result. Mediums can give the paint a very good consistency, and the finish looks good as well. 

When picking a pouring medium for acrylic paint, make sure to pick one with good quality. Liquitex, Floetrol, Atelier, are some of the top-notch pouring mediums for acrylic.

Here’s how to remove lumps or chunks from acrylic paint using a medium:

  1. Take the paint on a palette or a plate and loosen the paint using either a normal knife or a palette knife.
  2. Now, add the medium using a dropper. The ideal ratio for mixing medium is 1:2, indicating you must use 2 parts of medium for 1 part of paint.
  3. After adding the medium, if you feel the paint is thick, add a few drops of water as well. 
  4. Then thoroughly mix the paint. Slowly you’ll see the lumps and chunks disappearing.

How to Fix Lumpy Acrylic Paint on Canvas?

After painting, if you see the paint on the canvas has some lumps, then the best way to take them out is using a tweezer. As you know, acrylic paint dries very fast, therefore, you’ll have to remove all the lumps before the paint dries. 

You require to be very gentle when picking the lumps, pushing hard can damage the painting. However, if you slip a bit while removing the lumps, don’t worry, as long as the paint is wet, a paintbrush will undo your mistake. 

If you pick a lump from dry paint, then that’s most likely to leave a spot that can make the entire painting look bad. In that case, after removing the lump, you can fill the spot with a suitable paint.

If you’re planning to get acrylic nails, here’s how long it takes to do acrylic nails.

Can I Fix Lumps In Already Cured Paint?

Lumps in already-cured paint can be frustrating. But the good news is, you can fix lumps in already-cured paint. Here’s how you do it.

Pick 220 or 320-grit sandpaper and gently sand the lumps. Be careful, you don’t want to sand areas that are in good condition. Once the surface becomes even, clean the surface thoroughly with a brush to remove all the sand dust. 

Then add new layers of paint. You might need to add multiple layers of paint to achieve the desired finish. 

How to Prevent Acrylic Paint from Getting Lumpy?

Below we’ll talk about the most common reasons why your acrylic paint may become lumpy and how you can avoid them. 

Check If There’s Any Leak in The Container

The most common reason behind acrylic paint getting lumpy is a leaking container. If the steel container is rusty, then chances are high that there are leaks already.

In most cases, a rusty container lid comes with a bunch of tiny holes which can’t be seen with the bare eye. But they’re good enough for air to pass in. And once air gets inside the container, the paint will get lumpy real fast. 

Sometimes, it’s the user’s fault. When they’re done using the paint, they forget to close the lid securely. And that’s what leads to lumpy paint.  

Therefore, if you find the container rusty, it’s best to transfer the paint to an air-sealed container. If you can store acrylic paint properly, it will easily last for more than 10 years. 

Store The Paint At Right Temperature

Excess cold and heat both are reasons for lumpy paint. A temperature of more than 36 degrees C is enough to make the paint too thick.  Similarly, freezing cold temperatures will also make the paint chunky. Therefore, the paint container should not be placed where it’s exposed to extreme heat or cold. The ideal temperature range for storing acrylic paint is 16 C – 26℃.

Be Aware of Expired Paint 

It’s another common reason why paint gets lumpy or chunky. All paint comes with an expiry date of 5-10 years on average, after that time, the paint will start to get lumpy. Not only that, the paint will get rubbery, too, due to microbial contamination. 

Avoid Using Low-Quality Paint 

Cheap quality acrylic paints get lumpy or chunky pretty easily, and there is nothing you can do about it. What’s worse is that once these paints get lumpy, they’re extremely hard to fix. Here are some high-quality acrylic paints that you can use:

  1. Liquitex Basics Acrylic Paints at JOANN
  2. Winsor & Newton Professional Acrylic Paints
  3. Blick Studio Acrylic Paints

Mix the Paint Properly 

If you’re not properly mixing any type of medium or anything else with acrylic paint, that can also cause lumps.

Mixing paint, though, seems like a piece of cake, it requires patience and arm stamina. 

When adding medium, make sure to maintain the ideal ratio. The Ideal ratio for pouring medium is 3 parts of medium to 1 part of paint. After adding, stir the paint properly with a knife or a stick. To mix acrylic paint properly, you must at least stir thoroughly for 5-10 minutes. 

Apply Thin Layers Instead of a Single Thick Layer 

When you apply thick coats of acrylic paint, they might give a lumpy effect. Therefore, it’s best to apply multiple thin coatings instead of one or two thick ones. And try to take less paint on the brush for a smooth finish. 

After applying one layer, wait for a few minutes and then apply the next layer. Adding layers fast can also lead to lumps.

In case, you’re one of those who love miniature paintings, Citadel acrylic paint will be a high-quality option for your projects!

Clean The Dirty Lids 

Most people make this mistake. After opening the lid, if it’s kept on a dusty surface and then it’s put back on the paint container without proper cleaning, that can cause the paint to become chunky. Before you close the paint container, wipe the lid with a clean cloth. 

Frequently Asked Questions 

Why is my acrylic paint so thick?

There are various reasons why acrylic paint gets thick. The most common one is loss of moisture. When the paint is exposed to air, it loses moisture and becomes overly thick. Then extreme temperatures are another factor leading to thick acrylic paint. 

How to fix lumpy acrylic paint on latex?

When the acrylic paint is wet, you can use a tweezer to remove the lumps one by one. If removing these lumps leaves any marks, paint those spots with the same color. 


If you want no hassle and want to remove the lumps from the paint as fast as possible, then strain the paint. The flaw of straining paint is that some paints are wasted during the straining process. But the best way is to use a medium or water to remove lumps. 

Whatever it is, we hope this guide taught you how to fix lumpy acrylic paint all by yourself.

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