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8 Tips on How to Seal a Mural Painting

8 Tips on How to Seal a Mural Painting

The age-old struggle for any painter is how to seal a mural painting.

For the daring sort who paint outside or on walls exposed to people, this struggle is even more real on how to protect a wall mural.

If you are an artist being commissioned to paint a mural, chances are that you are thrilled.

However, there is no way that you want to be responsible for painting a masterpiece that won’t last. In a perfect world, everything that you paint would be immortalized for all to behold.

In reality, there are many steps that you must take to keep your mural on the wall.

Ensuring the long life of your precious mural requires effort, but it is worth every single step.

That’s why we’re taking a deep dive into looking at how to seal a wall mural.

We’ll be looking at how to pick the best varnish for murals, including the best varnish for indoor murals and the best varnish for outdoor murals.

Some precautions must be taken before, during, and after to keep your painting safe.

For the best possible results, you will want to make sure that you put every effort in.

Doing more work now can save you a lot of heartaches later. This will make it more likely that your mural will be around to stun visitors for years to come.

In addition to these tips, go to my Recommendations page where you will get exclusive tools that will help you create art no matter where you are and/or services that will help you grow your art business.

mural on the wall pin

Preparing The Wall For The Long-Term Mural Protection

Before you even think about painting a wall mural, you must consider the wall.

The right method for how to seal an outdoor mural painting depends on the wall material and requires a few precautions.

Understanding how to seal an indoor mural is easier but still requires some thought. If you want your painting to last, then you need to make sure that your canvas is in order.

This involves surveying the wall for damage and then preparing the wall for your painting.

Taking these precautionary steps will help your mural on the wall stay where it should.

For best results, take your time here. You will not be able to do anything after the painting has begun.

The First Thing You Need to Do

Your first step on how to protect a wall mural painting will be to evaluate your surface. This means checking for any existing damage or rot that might impact your painting ability.

For indoor walls, you will want to make sure that you don’t have any damage that cannot be painted over.

For outdoor wall murals, you will want to check for any rotted areas that might be likely to give way over time.

When you pull out your outdoor mural sealant, you don’t want to have missed anything in these preparatory stages.

In both instances, if you find any sort of damage, you will want to repair the wall.

It will not do to have the wall give way after your painting is done.

After you have ensured the structural integrity of your wall, you can begin with preparing the wall. Your first step in preparing a wall is to clean the surface.

Cleaning your wall before painting will help ensure that the paint sticks to an even surface.

If there is dirt and grime on the wall, this will impact the quality of your painting area.

Worse, a dirty wall can muck up your brush and cause bigger problems down the line.

These steps are important before you use a mural sealant, as they build the right foundation for your mural.

For outdoor walls, consider spraying down the surface and scrubbing as needed.

Pay Attention and Avoid This…

A large mistake that people make is assuming that their indoor walls are clean when they are not. Even if they look clean to the naked eye, there is very likely dirt or dust.

Save yourself a future headache and wipe down the wall so you have a clean surface to work on.

Next, you’ll want to ensure you know how to seal a mural.

After the wall is completely cleaned, you will want to add a primer to the wall. Using a primer is a great way to give your paint a little extra stick when you apply it.

Primer is especially important for preparing for an outdoor mural sealant.

This will help your paint bond with the wall so that it is less likely to wash away over time.

A solid coat of primer can successfully take your paint and help it settle in for the long term. For the best possible effect, it can be beneficial to remove all other paint from the wall before starting.

This will help ensure that everything is sticking to a reliable surface if the previous person skipped using primer.

mural on the wall primers
Display of some common paint primers you’d find in a store.

Use the Right Kind of Paint

An easy mistake for artists to make is using the incorrect kind of paint.

This can already start you off on the wrong foot when considering how to protect a wall mural.

When you are working to evaluate what paint to use, you will want to consider a few things. Different kinds of paint are best for different surfaces and environments.

This is why choosing the right paint will help you keep your mural on the wall longer.

Acrylic paint is standard for the type, but you’ll still have to learn how to seal acrylic paint on wall types of different kinds, such as indoor and outdoor, plus different base materials.

Understanding these differences will help you to find the right product for your masterpiece.

Finding the Right Type of Paint to Protect Your Wall

The simplest approach to finding the right kind of paint is to consider your circumstances. One key factor that proves to be continuously relevant when it comes to your work is the surface.

Certain paint types are better for specific surfaces.

Understanding this will help you know what to look for.

You will need something more heavy-duty for an outdoor wall than an interior wall.

Figuring out how to seal an indoor mural is generally easier than finding the best varnish for outdoor murals.

Most paints will tell you what surfaces they are good for.

mural on the wall paint surfaces
(Left) One common area to see the appropriate surfaces to paint on is the front, which is marked by the highlight. (Right) On the back of every paint, you will see the appropriate surfaces to paint on, which is marked by the highlight.

Beyond the surface, you will want to consider the elements.

Some paints are more prone to fading with sun exposure.

Especially if you are wondering how to seal an outdoor mural painting, sun exposure is a big factor. Others are easily influenced by drastic temperature changes.

Knowing what kind of area you are painting in will help you to avoid these pitfalls.

For an interior wall, this is less of a concern unless you have specific circumstances like an indoor pool.

Once you know where you are painting and what the area is like, you can make your decision. In most instances, the paint options you look at will tell you what circumstances they work in.

Looking at the label is generally a great way to find out if they are appropriate for a surface or temperature range.

Most outdoor paints that you buy locally will hopefully consider the area and provide appropriate options.

In addition, you’ll also want to get an exterior mural varnish for your mural protective coating.

Use A Good Varnish To Seal A Mural Painting

Varnish is an incredibly powerful tool for preserving your paintings.

It’s one of the main methods for how to seal a mural painting.

When learning how to seal acrylic paint on wall, a varnish will be one of the major tools in your arsenal.

These are often referred to as sealants, which means that they seal in your paint. There are various kinds of varnish just like there are paint, and each has its benefits.

Varnish is also called clear coat for murals, along with other names, such as mural protective coating.

Some of these are best used for specific kinds of surfaces or elements.

Some varnishes will be more effective indoors or outdoors. Once again, keep this in mind when you begin shopping and looking at the labels.

A good varnish does the job of adding a protective top layer to your painting.

This is especially important for outdoor murals, which need an exterior mural varnish.

This is important because it can help you to provide an extra layer of protection between your painting and the world.

To keep your mural on the wall, you will without question want to add this extra layer.

A couple of coats of varnish can go a long way when it comes to preserving the life and coloring of your paintings.

The best varnish for murals depends on a variety of factors, so go explore!

How To Seal A Mural Painting By Using Good Varnish The Right Way

For an effective use of varnish, you will want to wait until the paint is completely dry, especially for outdoor mural sealer.

After this is in order, you will apply layers of varnish and allow them to dry as needed.

Next, we’ll look at how to seal a wall mural.

Since these products vary widely in terms of their actual composition, it is best to read the instructions. Generally, the varnish will tell you how many layers to apply when using the product.

mural on the wall paint varnish
Every varnish will tell you the right amount of coats to apply on your paint, which is marked by the highlights on the image.

Varnish can help to protect a wall mural in several ways.

When learning how to seal a mural, you’ll find, these products can protect from dirt and water and can sometimes even offer a shield against sunlight.

The differences in these products is sizable, but there is without question one out there to suit your needs.

You will likely need something less intense for indoor wall murals than you would outdoor wall murals.

If you’re interested in painting, check out our other painting-related content:

How to Protect a Wall Mural for a Long Time

Let’s look at how to seal a mural painting for a long time.

For acrylic painters, isolation coats are considered general practice.

This method allows you to provide an additional protective layer between your paint and the varnish.

It can also help add a layer of protection when it comes to keeping your mural on the wall.

Isolation coats should only be used with acrylic paint, so if you go with a different route, you can skip this section.

However, isolation coats are believed to be an excellent way to preserve the life of a wall mural.

Benefit of an Isolation Coat

The true benefit of an isolation coat is the fact that it acts as a backup to a good varnish.

It’s a great step in how to protect a wall mural most fully.

An isolation coat is a clear coat for murals that goes between the varnish and paint, adding an additional layer of protection.

This can be incredibly helpful for outdoor wall murals that might be facing the elements.

A varnish is not an impenetrable force.

Since this is the case, when your varnish wears out, you want to have another layer. For acrylic paints, an isolation coat can act as an additional method of protection.

This will keep your painting going strong for years to come!

You can buy an isolation coat where you would buy the rest of your supplies to keep your painting safe.

Remember, this is different than varnish for outdoor murals, as it’s what provides an additional protective layer between the paint and the varnish coat.

Make sure that you let the paint completely dry before applying this layer.

It will ensure the structural integrity of your painting so that you can admire it for a nice long time!

The Case for Mural Protection Products

There’s another layer available if you go above and beyond just a varnish for outdoor murals.

If you are looking to keep your painting in fighting shape, you might want to consult the pros and grab a mural protection product.

While varnishes and isolation coats can be a good defense, some companies think beyond that.

One of those companies is MuralShield, which offers its collection of products.

Mural Shield itself is one of a number of products it offers for mural protection. This company, and others like it, are here to help you get the most out of your wall murals.

They offer multi-step processes and products to keep your murals protected.

Though many believe that more traditional methods are fine, others are trying these new products.

The use of true shields to protect wall murals from the elements is one way to protect your work. These companies are focused on maintaining wall murals specifically.

This means that their products are completely geared towards this focus.

These products are more focused than their one-size-fits-all counterparts.

Products like these are being used around the world today as mural protection. Since wall murals are becoming more popular, cities rely on these products to keep their art safe.

Especially if you want it to last decades in a difficult outdoor environment, a mural shield is a good idea.

Assuming that you are working on a commission, you might want to help protect your work that much more.

These products can even help keep your paintings from being defaced with graffiti or other damage. It makes them an ideal option for keeping your mural on the wall as the ultimate mural sealer.

Applying Mural Protection in The Right Temperatures

One major factor to consider when you are putting a mural on the wall is the temperature.

A mural sealant is only as good as it can withstand the wall’s expansion and contraction.

Temperature can help or hinder your process every step of the way. To get the most out of your painting, review your products for temperature limits.

In most cases, paints and varnishes are meant to be applied at specific temperatures.

Though it is generally a forgiving range, falling outside of these temperatures can be problematic for many a mural sealer.

To avoid your mural being compromised, always review these requirements and act accordingly.

mural on the wall paint temperature
To find the appropriate temperatures to use paint look on the back of the paint can under the “Application” section.

Proper Surface Preparation and Primer Application

Preparing the surface is crucial for the mural’s durability and appearance. Here are the steps to take before applying primer:

  1. Clean the surface thoroughly, removing dirt, debris, and any existing paint or coatings.
  2. Repair any cracks, chips, or imperfections in the substrate.
  3. Apply the primer evenly, following the manufacturer’s instructions. Allow it to dry completely.

Applying a Protective Sealant

To protect your mural from UV rays, moisture, and pollutants, apply a protective sealant. Consider the following types of sealants:

UV-Resistant Clear Coat

A UV-resistant clear coat provides a protective layer that shields the mural from sun damage, helping to maintain its vibrant colors.

Graffiti-Resistant Sealant

Graffiti-resistant sealants protect murals from vandalism by allowing graffiti to be removed easily without damaging the artwork.

Water-Repellent Sealant

A water-repellent sealant prevents moisture from seeping into the mural, reducing the risk of mold, mildew, and substrate damage.

Routine Maintenance and Cleaning

Regular maintenance and cleaning will help preserve your mural’s appearance and prolong its lifespan.

  • Inspect the mural periodically for signs of damage or wear.
  • Clean the mural gently using a soft brush and mild detergent to remove dirt, grime, and pollutants.
  • Address any damage or fading promptly to prevent further deterioration.


For some, protecting a wall mural might feel like busywork.

Most artists are thrilled to be painting, but few of them are as excited about the maintenance work.

Though it might not seem like a ton of fun, taking these steps can help you in the long run. There is nothing more tragic than painting a mural and then finding it cracked and broken a year later.

Protecting your art is as important as painting it, so go the extra mile.

Though it might sound like a lot of work, taking these steps will save you in the long run.

You might even be surprised to find that these processes are not as bad as you think. A few extra layers of varnish and some wall cleaning are a small price to pay for protection.

In the end, you will be glad that you did.

Also, if you want exclusive tools that will help you create art no matter where you are and/or services that will help you grow your art business, go to my Recommendations page.

Do you paint wall murals?

Seal a Mural FAQ

What do you seal outdoor murals with?

To seal outdoor murals, use a UV-resistant clear coat or a graffiti-resistant sealant, both of which provide a protective layer to the artwork.

These sealants shield the mural from sun damage, moisture, and vandalism, ensuring the colors remain vibrant and the mural stays intact for a longer time.

What paint is best for outside murals?

The best paint for outdoor murals is artist-grade acrylic paint, as it offers high pigment concentration, UV resistance, and excellent adhesion.

Additionally, some manufacturers produce mural paints specifically formulated for outdoor use, designed to withstand harsh weather conditions and provide long-lasting color retention.

How long will an outdoor mural last?

The lifespan of an outdoor mural can vary greatly, depending on factors such as the quality of materials used, surface preparation, and maintenance.

With proper care, high-quality materials, and protective sealants, outdoor murals can last anywhere from 10 to 20 years or even longer.

Jae Johns

Tuesday 26th of April 2022

you're welcome


Saturday 28th of August 2021

Thanks for the article! My son's elementary school's PTA asked me to touch up and seal a mural that's on a wood handball wall on the playground. It wasn't sealed originally, done 2 years ago I think (no idea why it wasn't sealed). Any advice on how to fix this? Also, it's in a forested coastal area, lots of elements, salty air, and direct sunlight. Thanks for any tips!

Jae Johns

Tuesday 31st of August 2021

If it wasn't sealed originally, I'm not sure how you would fix it.

Dawn Barry

Thursday 14th of January 2021

Wow. I really like your post. Thanks I have landed here. I have seen the same thought on painting from walthampaintingcompany blogs and I’m so in love with some design projects in your content as well! I do love mural painting! I thought that i could find a good solution for our painting project, a crazy idea just was born right now! I think it boost a great level of richness to our house ! Thanks for the very helpful information. Best of luck!! Big thumbs up~Barry~

Jae Johns

Thursday 14th of January 2021

I'm glad it really helped you, Dawn. Good luck with your project!

Zoe Campos

Wednesday 4th of March 2020

Thank you for telling me that a good varnish will be able to provide an extra layer of protection and will also help in preserving our paintings. For a school project, we were tasked to paint a mural on the right wall of our college building and I wanted other students to witness the message we want to convey through our art. We won't be able to do that if our murals will not withstand the test of time, so I'm really thankful for your article.

Karen Strang

Tuesday 12th of January 2021

@jaejohns, I am restoring an acrylic outdoor mural originally done in 1999. Also, did a mural on a rock at a local horsefarm. I want to coat them to withstand the elements and have only layered polyurethane after each painting session. Can I still use a product such as mural shield?


Wednesday 25th of March 2020

Awesome! I'm glad my article can help. I hope the school project turns out well!

Derek McDoogle

Tuesday 25th of February 2020

I like how you said that your first step on how to protect a wall mural painting will be to evaluate your surface. My sister owns a beautiful house and she would like to add her own style by decorating her walls. Since there is a huge wall in her living room, it would be a great idea to paint a mural so that she can give the look that she is looking for.


Wednesday 25th of March 2020

That's great to hear! I hope the mural comes out great, if she does do it.

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