Dried Acrylic Paint? Do This To Rehydrate Acrylic Paint

Last Updated on February 13, 2025 by Masha Eretnova

You may have stored some paints and later find dried-out acrylic paints or use a paint-by-number kit and some color will be hardened in the bottles. If this happens to you, learning how to rehydrate acrylic paint is the solution.

Even though acrylic paint is water-soluble you can only rehydrate acrylic paint that has some moisture and is still glossy.

You can revive drying acrylic with warm water or acrylic flow improver. Totally dried acrylic paint cannot be reused or reactivated, you have to buy new paint

This article will guide you on how to rehydrate dry acrylic paint and even prevent it from drying out. Read on to save the dried-up paint!

I will go over easy methods, some risky DIY ways, and extra tips to prevent acrylic paints from drying.

I will be honest with you and tell if I think it is a good or bad method to try.

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Why is my acrylic dried out or hard?

Acrylics are water-based with pigments floating in acrylic binder and water. Once water evaporates, acrylic paint dries and forms a plastic-like film on the painting surface.

This process makes acrylic paint water-resistant and not hard to wash off and it takes only up to 30 min.

Reasons why you have hardened acrylic paint:

1. The old paint was exposed to a lot of air. This effect also takes place when you forget to put the lid back on. The acrylic paint will be completely hard within a week.
2. Direct sunlight or extreme temperature (both cold and extreme heat in a dry climate) gets into the area where the paint is stored.
3. You didn’t mix the paint properly before use.
4. You added too much water to the paint before painting. More water = more evaporation.
5. Putting too much paint on the palette as acrylic paint can dry in just a matter of 10 to 20 minutes.
6. Low-quality paint will likely dry out even if it’s still in the paint container as it has fewer pigments and no-name binders.

There are several ways to rehydrate drying acrylic paint that still contains some moisture. Drying paint may become lumpy and rubbery, it will spread unevenly on the painting surface. 

Sometimes you can fix it by mixing it well with a palette knife, but if it doesn’t work, check one of the methods below.

The best methods To Revive dried acrylic paint:

✅ Safe & Effective Methods:
✔ Warm Water – Gently revives slightly dried paint
✔ Fluid Medium – Restores consistency & flexibility
✔ Flow Improver – Enhances smoothness & flow
✔ Sanding – Fixes dried paint on canvas
✔ Glazing Liquid – Helps rehydrate paint layers
✔ Gesso – Prepares surface & can help reactivate paint
✔ Pouring Medium – Restores fluidity for pouring techniques

❌ Risky & Not Recommended:
🚫 DIY Flow Aid Medium – Unreliable & can ruin paint
🚫 Toothbrushing with Water/Alcohol – Can damage paint layers
🚫 Adding Oil Paints – Unstable & can separate over time
🚫 Acetone – Too harsh; can break down acrylics
🚫 Mixing Sanitiser with Baking Powder – Risky chemical reaction
🚫 Microwave – Uneven heating & possible paint fumes
🚫 Blending with Fresh Paint – Can alter texture & consistency

So ultimately, most of the DIY methods recommended online won’t work.

I understand people said it worked for them, but if we truly understand the composition of acrylic (polymer, pigment, preservatives, water) we won’t add a dishwasher to it and expect it to be artist-grade brand-new paint.

Let’s stay rational, my friends!

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How to rehydrate Dried acrylic paint

Don’t lose hope when you see your acrylic paint that turned dense, and heavy. There’s a chance to revive it with warm water and a flow improver as long as the paint has a little moisture in it.

This method also helps if you think you have thick heavy body paint and you want to make it more fluid.

Add warm water

Warm water is like a magical potion in restoring acrylic paint that turns hard and clumpy. It doesn’t only work wonders but it doesn’t thin out the paint. The temperature of water improves the paint’s solubility.

After adding a drop of warm water, stir the paint with a small toothpick or a wooden stick. If you feel it is not enough, add a little more water.

It’s best to let it sit overnight and check the outcome the following day. Before you leave it, make sure that the pods are tightly sealed to prevent air from messing it up.

Read also: How to Thin Acrylic Paint: 3 Correct Ways & 3 Dont’s

Make sure to not add more than 25-30% of water to your paint,if you will add too much water you will end up with watery paint.

This method may not work with fabric acrylic paint.

Add Flow Improver

Using a flow improver is one way to put hardened or thick acrylic paint into use. Unlike warm water, flow aid mediums don’t break acrylic paint composition and only improve the consistency.

You can directly mix it with paint or prepare a cup with water to wet your paintbrush and put a few drops of flow improver in it. This is done before you start painting.

The Max ratio is 25% of flow aid to paint.

Dip your brush into the cup then into your paint.

You’ll notice that the brush moves smoothly over the painting surface. But you should be aware that flow improver thins the paint and it may turn more transparent.

If these methods didn’t work your paint is not just thick, it started to really dry out, the hard paint doesn’t have a bit of moisture left.

Read also: How to Fix Lumpy & Chunky Acrylic Paint? [10 Easy Methods]

Add fluid acrylic medium

The simplest way of rehydrating acrylic paint is by adding a liquid acrylic medium. Liquitex offers archival matte or gloss fluid mediums that help improve and enhance the blending and flow of the paint.

You can start with a small amount of paint and mix the medium. You should know that this mixture makes the color more transparent compared to the original pigment. Don’t add more than 1/4 part to 1 part of the paint.

Use Water or alcohol with a toothbrush

Normally, you should avoid mixing or thinning water-based paint with alcohol. But some crafters report that it helped rehydrate dried paint. I would first try the same with water.

You need isopropyl alcohol (50% to 99%) and an old unused toothbrush.

1. Dip the toothbrush into the water or alcohol. It would give you 20 to 30 drops of the said liquid which is enough for 100 ml of paint.
2. After adding water or alcohol, gently rub the brush to encourage rehydration. The goal is to make the paint spread evenly on the surface during application. Work on a glass palette.
3. When rehydrating dried acrylic paint, you have to pay attention to its consistency. That’s why you have to gradually add water. Excessive amounts can make the paint weak. It leads to blooming, an effect where you can’t control the spreading of the paint on the canvas.

Alternatively, you can just add a few drops of isopropyl to your paint jar, and then add warm water. And mix it with a wooden stirring stick.

Add Acrylic glazing liquid

If you want to add gloss and rehydrate your acrylic paint at the same time, get acrylic glazing liquid. It is primary function is to extend the drying time which is exactly what we need!

Liquitex and Golden both have great options in satin or gloss finishes.

You’ll only need a small amount of this liquid to revive your dried paint – 1/4 part max. In addition, you have the liberty to add more if you want to intensify the color or the gloss. 

Add Gesso

Gesso is mainly used to prime canvases and it is a white, grey, or black thin medium. Gesso is akin to white acrylic paint but it’s on the thinner side.

Put some of the drying paint on the palette and some amount of gesso. Mix so you can come up with the texture that’s great for painting. 

Use Pouring Medium

Pouring medium reduces the tension and makes acrylic paint fluid and durable. There are dozens of pouring mediums on the market, from well-branded Floetrol to glue-based affordable Mont Marte pouring medium.

Each pouring medium has its own best ratio for mixing pouring paint, but we don’t need to follow it as we are not creating easy-to-flow paint, we simply need to rehydrate our dried acrylics.

Start by adding a few drops and not more than 25% of the pouring medium to the paint. Unless you really want to make it flow.

Risky Methods That Won’t Help You Revive Dry Acrylic Paint

I would not try any of the following methods to restore dried-out paint, and all paint manufactures will tell you the same. Despite all the DIY pseudo-advice out there.

But if you don’t want to buy a new bottle of paint under no circumstances, and are ready to risk, you can keep reading.

Homemade Flow Aid

You’ll need half a teaspoon of the dishwasher and a small amount of water should be mixed properly.

Combine this mixture with the dried paint and stir them gently to achieve an even texture. 

I would not recommend it to use with artist-grade expensive paints or for paintings you are planning to sell.

Mixing acrylic with oil paint

Another DIY and risky method, that still exists out there, is to add oil paint.

Well, normally, mixing oil and acrylic is a bad idea as we all know it is practically impossible to mix oil and water, one will sit on top of the other, so the mixture will be separated inside the plastic container.

Yet, my fellow crafters successfully restored the body of the acrylic paint with oils. But you have to know that the colors of the acrylic paint will change once you add the oil paint.

Mixing Fresh and Dried Acrylic Paint In a Blender

Yes! Fresh acrylic paint can be mixed with the dry one but you’ll need a blender. Only mix the same brand, as you don’t know exactly the composition of all brands and how they will interact.

You will need an airtight container where you can store newly mixed paint.

1. Cut the tube to access the dried paint.
2. Break the hard acrylic paint into chunks.
3. Put the fresh acrylic paint into the blender before the hard chunks. This is to ensure that no chunks can be missed by the blender and that the color becomes smooth.
4. Add a little amount of water for dilution and blend to even out everything.

I don’t think the blender will be usable for food afterwards.

Melting Acrylic Paint In Microwave

Yes, some crafters came up with this “technique”. I would not guarantee that it will work and the acrylic paint will definitely lose its archival qualities if you will put it in heat.

If you are risky, you can try:Cut the tube

1. Transfer the dried paint to the microwave-safe container
2. Add a little bit of water
3. Microwave for 30 seconds and stir.

Mixing Dried Out Paint With Acetone

If the acrylic paint is hard as a rock, you need acetone, a kind of thinner. This substance can soften dry, hard acrylic paint. Due to its alcoholic content, acetone can gradually break down thickened substances.

But you don’t want your hard chunks of acrylic paint to completely dissolve, make sure you follow the 1:3 ratio of acetone to acrylic paint which is enough to soften the dried paint. 

Yet, as with alcohol, acetone and other solvents are not ideal for acrylics. I would not risk it, but I know that crafters still do that.

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FAQs

How to fix dry paint from your paint by number kit?

Paint by numbers kit includes acrylic paint in small cups with loose lids. But you’ll find some dry colors that can crack or flake.

You can fix it with a drop or a little warm water. Another way to loosen the paint is to spray warm water. A brush or palette knife can help you scrape the dried paint on the sides.

Besides water, flow aid improver or thinners can be used to fix the dry paint from your paint-by-numbers kit.

A blow dryer can turn the paint into liquid, especially if you’re painting in a humid place. Give a 6-inch gap between the paint and the dryer. Let the heat from the blower work on the dried paint for a few minutes. It should be done before you start with your project and you may need to repeat it while you’re painting. 

Brands like MyPaintNumbers even offer to replace your dried paints.

Can you reactivate acrylic paint with water?

You can reactivate acrylic paint with water as long as it has a bit of moisture left in it. Adding water should be done slowly and no more than 1/3 of the volume of the paint.

But thin, dried layers of acrylic paint can’t be reactivated with water. That’s why it’s important to clean the palette after use.

What to do with old acrylic paint?

Acrylic paint can be kept unopened for 10 years. As mentioned, you can revive dried paint with water, a flow improver or fluid additive.

But some circumstances won’t allow it.

You cannot really see acrylic paint expire, but when the paint is opened and left unattended for 2 to 3 years, mold can develop or it will dry out.

Mold is not a good sign as it discards the moisture left in paint which is necessary for rehydration. If there’s no small amount of moisture in acrylic, you can’t revive it.

The presence of mold gives off a sour, mildew smell so you will be able to tell if the paint has gone bad.

Summary

Don’t lose hope when you feel like your acrylic paint paint is drying too fast. Be patient to rehydrate it with the help of warm water, a flow improver or fluid additive, and thinners like acetone.

You have to slowly add either of these substances in a small amount to end up with the desired consistency of the paint.

It’s also crucial to know if you can rehydrate dry acrylic paint or not. Reviving acrylics is impossible if it has mold or was dry for a few months.

To avoid ever needing to reuse dry paint, use wet palette and acrylic mediums when painting to keep acrylic from drying in the future.