Isolation Coat For Acrylic Painting | Importance, Recommendations, And Application 

Are you tired of your acrylic paintings losing their shine over time? Do you want to protect your artwork from the harmful effects of dust, moisture, and UV rays? 

If yes, then you’ve come to the right place. In this blog post, I’ll discuss everything you need to know about isolation coats for acrylic painting.

But what is an isolation coat? Well, It is a thin layer of clear acrylic medium that is applied over a completed acrylic painting before the varnish. 

Its purpose is to create a barrier between the paint layers and the varnish, protecting the paint from any potential damage caused by the varnish application.

It is motivating to know that many well-known artists also recommend the use of isolation coats in their painting process, including abstract painter Jackson Pollock and contemporary artist Chuck Close. So let’s learn more about it. 

Isolation Coat Vs Varnish, What Is The Difference? 

An isolation coat and varnish are two different types of protective coatings used in art conservation and preservation.

An isolation coat is a clear, non-yellowing layer of a medium such as acrylic polymer that is applied to a painting or other artwork before the final varnish layer. 

Its purpose is to create a barrier between the paint layer and the varnish layer, preventing any discoloration or chemical reactions between the two layers. 

On the other hand, a varnish is a clear, protective coating that is applied to the surface of a painting or other artwork to protect it from dust, dirt, and other environmental factors. 

Varnishes can be removable or non-removable, depending on the type of varnish used. 

Removable varnishes can be easily removed with solvents, while non-removable varnishes are more difficult to remove and are often used for long-term protection of the artwork.

Is Isolation Coat Necessary For Acrylic Painting?

Yes, an isolation coat is necessary for acrylic painting. Without an isolation coat, the varnish that is applied over the painting can cause the paint to soften or even dissolve. 

This can lead to a loss of color and detail in the painting, as well as possible wear over time. 

The isolation coat serves as a protective barrier between the painting and the varnish, ensuring that the painting remains intact and preserved. 

Additionally, the isolation coat helps to improve the adhesion of the varnish to the painting, resulting in a more even and durable finish. 

All around, the use of an isolation coat is a crucial step in the process of varnishing an acrylic painting.

Is Varnish Without Isolation Coat Worth It?

While it is possible to apply a varnish without an isolation coat, it is generally not recommended. Applying a varnish directly onto the paint layer can cause a number of problems over time. 

For example, the solvents in the varnish can cause the paint to become sticky or even dissolve, particularly if the paint layer is not completely dry. 

In addition, the varnish may be yellow over time, which can alter the appearance of the painting.

While it may be tempting to skip the isolation coat step, it is generally not worth the risk to the longevity and appearance of your artwork. 

By taking the time to properly prepare your painting with an isolation coat, you can help ensure that it remains protected and looks its best for years to come.

How To Apply Isolation Coat? Step By Step

Applying an isolation coat to an acrylic painting is a relatively simple process that can be completed in just a few easy steps. 

Here’s a step-by-step guide on how to make isolation coat:

Step 1: Gather your materials

You’ll need the following materials to apply an isolation coat:

  • Acrylic medium (gloss or matte)
  • A clean, soft-bristled brush
  • Water
  • Container for mixing the medium and water

Step 2: Mix the medium and water

Mix the acrylic medium with water in a 2:1 ratio (2 parts medium, 1 part water). Stir the mixture thoroughly until it’s well combined.

Step 3: Apply the isolation coat

Using a clean, soft-bristled brush, apply the mixture to the surface of the painting in thin, even strokes. 

Be sure to apply the isolation coat in one direction only, as this will help to prevent brush marks from showing up in the final varnish. 

Allow the isolation coat to dry completely before using the varnish.

Step 4: Sand the isolation coat (optional)

If you want an extra-smooth surface, you can lightly sand the isolation coat with fine-grit sandpaper once it’s dry. 

Make sure to wipe away any dust or debris with a clean, dry cloth before applying the varnish.

Step 5: Apply the varnish

Once the isolation coat is dry and sanded (if desired), you can apply the varnish to the painting using a clean, soft-bristled brush. 

When applying the varnish, ensure that you brush it in smooth, consistent strokes, taking care not to over-brush or create any bubbles. 

It’s important to give the varnish enough time to dry completely before handling the painting, as any premature contact could result in smudging or smearing of the varnish.

Pro Tip:
Remember, the key to applying an isolation coat successfully is to work slowly and carefully. Take your time, and be sure to follow the above steps closely for the best results.

What Can I Use For Isolation Coat On Acrylic Painting?

For an isolation coat in acrylic painting, you can use a clear acrylic medium. This could be either gloss or matte, depending on your priority. 

The following are considered the best isolation coat for acrylic painting: 

  1. Liquitex Gloss Medium and Varnish: 

This medium can be used as an isolation coat, as well as a final varnish. It dries clear and glossy, providing a smooth surface for the final varnish layer.

  1. Golden Polymer Varnish with UVLS: 

This varnish is designed to protect the artwork from UV light and other environmental factors. It can also be used as an isolation coat before applying a final varnish layer.

  1. Winsor & Newton Professional Acrylic Mediums: 

This line of acrylic mediums includes several options for isolation coats, including their Clear Gesso and Acrylic Glazing Medium. These mediums provide a clear, even surface for the last varnish layer.

  1. Gamblin PVA Size: 

This product is specifically designed for use as an isolation coat for acrylic paintings. It dries clear and creates a fence between the paint layer and the final varnish coating.

Pro Tip:
Always test your chosen isolation coat on a small area of your artwork before applying it to the entire surface. This will help ensure that the medium is compatible with your paint and does not cause any adverse reactions.

Can You Use Spray Isolation Coat For Acrylic Painting?

Yes, you can also use a spray isolation coat for acrylic painting. There are several brands of spray varnishes and mediums that can be used as an isolation coat.

One popular brand is Krylon’s UV-Resistant Clear Coating. Other brands that offer spray varnishes suitable for use as an isolation coat include Liquitex and Golden.

When using a spray isolation coat, it’s important to apply it evenly and thinly over the entire painted surface. 

Be sure to follow the manufacturer’s instructions for proper use, including any recommendations for distance from the artwork and the number of coats to apply. 


Should I coat my acrylic painting?

Yes, it is recommended to coat your acrylic painting to protect it from dust, dirt, and UV rays that can cause fading and discoloration over time.

Do I really need an isolation coat?

Yes, it is highly recommended to apply an isolation coat before varnishing your acrylic painting. It creates a wall between the painting and the varnish, ensuring that the varnish will not bleed into the paint and spoil your painting. 

Why use an isolation coat on acrylic painting?

An isolation coat is important for several reasons. First, it helps to insulate the painting from the varnish, which can cause discoloration or damage to the paint if it seeps into the surface. Second, it creates a more even surface for the varnish to adhere to, ensuring a smooth and consistent finish. Finally, it can also make the painting easier to clean and maintain over time.

What to use to cover acrylic painting?

There are several options for covering an acrylic painting, including varnish, wax, or a clear acrylic spray. Each has its own benefits and drawbacks, so it is important to choose the option that best suits your needs and intentions.

How to coat an acrylic painting?

To coat an acrylic painting, first ensure that the surface is neat and dry. Then, apply an isolation coat if desired, followed by the varnish or other protective coating of your choice. Follow the instructions for the specific product you are using, and allow the painting to dry entirely before handling.

Is isolation coat acrylic painting ok?

Yes, an isolation coat is a safe and effective way to protect an acrylic painting. It is suggested by many artists and art conservation experts as a best practice for preserving the longevity and integrity of acrylic paintings.

Final Words

In conclusion, using an isolation coat for acrylic painting is a crucial step in guaranteeing the longevity and protection of your artwork.

This straightforward process significantly improves the archival quality of your artwork, providing better resistance against fading or damage over time. 

By taking this additional step, you can have confidence that your painting will retain its vibrancy and beauty for an extended period.

Thank You For Reading!

Jose Scott

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