Do I Need to Varnish an Acrylic Painting?

Congratulations on finishing your acrylic painting! Now that you’re at the finish line, you may be asking yourself, do I need to varnish this?

I varnish all my paintings, not only as an insurance policy against the ravages of time but also to even out the final sheen and resaturate my colors. I’ve noticed that my darker shades tend to flatten and become matte as they dry, and varnish restores their depth and luster. The result is an even finish, vibrant colors, and a painting protected from UV light, dirt, and pollutants.

So, do you have to? No, you don’t have to do anything. But do I recommend it? 100% yes.

A cautionary note: I always photograph my paintings BEFORE I varnish, simply because I use a gloss varnish, which creates glare. Photographing a shiny painting is a nightmare!

Before we dive in, if you're interested in a FREE 36 page eBook on acrylic painting that I've developed, you can download that here. It's been downloaded by over 12,000 artists, and I'd love for you to get a copy! 

How Do You Varnish an Acrylic Painting?

My go-to varnish for acrylic paintings is Kamar by Krylon. This spray-on varnish offers a glossy finish that enhances color vibrancy and restores the depth of darker shades. I apply two thin layers, allowing an hour of drying time between coats. Kamar is durable, doesn’t yellow over time, and provides excellent protection against UV light and pollutants.

While some artists use an isolation coat before varnishing, I find that Kamar works perfectly without it, thanks to its high-quality synthetic formula. However, if you’re concerned about removing varnish later, you may want to consider using an isolation coat for extra security.

How Do I Apply an Isolation Coat?

If you decide to use an isolation coat before varnishing, here’s how:

1. Mix soft gel medium (I prefer Golden) with 30% water (two parts gel to one part water).
2. Apply a thin, even layer to the top of your completed painting, being careful to avoid ridges. Work quickly to prevent the gel from drying mid-application.
3. Let it dry completely, and make sure to clean up any dribbles around the edges.

What Kind of Varnish Should I Choose?

When choosing a varnish, you’ll have to consider the sheen. Kamar by Krylon is my favorite because it’s recommended by fellow artists and provides a glossy finish that I love. However, you can also opt for a matte varnish, which will reduce gloss but may lighten darker areas of your painting. Satin varnish is a good middle ground, offering some sheen without being too shiny.

To decide what’s best for you, try testing different varnishes on small test pieces of canvas with varying colors and tones. This way, you’ll see firsthand how the varnish affects your painting’s look.

How to Apply Your Spray Varnish

1. Work in a well-ventilated room (I prefer my garage).
2. Elevate your painting above a piece of cardboard using items such as small cans of paint.
3. Shake the varnish can for the recommended time (usually two minutes).
4. Apply thin, overlapping layers in an S-pattern to prevent pooling.
5. Allow it to dry for however long the manufacturer recommends on the back of the can
6. Apply a second coat.
7. Let it sit for 24 hours before moving it inside. If needed, cover the painting with a box to protect it from dust.

Remember, varnishing can leave a slight odor, but it should dissipate within 24-48 hours with proper ventilation.

Final Thoughts

Varnishing your acrylic paintings is a great way to protect your work and bring out its full vibrancy. Whether you use an isolation coat or not, it’s important to experiment with different varnishes and sheens to find what works best for your style.

Have any questions? Let me know in the comments below, and happy painting!

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