Why varnish acrylic painting?

Varnish is the final step for painting. When I just started I was terrified – there were so many contradictory posts about varnishing but all of them said, you could probably ruin your painting…Wait, what? I avoided varnishing for a while but one day I decided just to try on a small painting. And that was amazing!

I start reading about it and I realized why I should varnish my acrylic painting: to protect it during transportation, to protect it from sun, humidity, and temperature changes, to make my painting look better and finished for 100 years. After all, cleaning a varnished painting is so easy!

Here is why I decided to share with you all I know and researched to make sure you are not scared anymore. I will start with a brief reminder of what is varnish and what types of varnish exist and cover 6 major reasons why you should consider varnishing your acrylic painting.

What is varnishing?

A varnish – is a transparent protective layer on our painting. It forms a hard, clear, shiny surface when dry.

Varnishing an acrylic painting means covering a finished and completely dried ( ±24 hrs.) painting with several coats of varnish.

What type of varnish to choose?

Varnish can be removable (which is better) and non-removable (permanent).

Basically, you need to remove and repeat varnishing every 5-10 years, because varnish collects all dust and dirt and can become yellow over time. If you’ve chosen permanent varnish you won’t be able to remove it and save your painting for longer years. If you will still try to remove permanent varnish, you can damage your painting.

Varnish can has matte, satin, gloss or high gloss finishes:

  • Glossy varnish slightly enhances the colors vivacity,
  • Satin and matte – soften the colors;
  • Matte varnish may make darker colors lighter.

You can choose any based on your preferences or mix them to achieve the desirable effect.

Natural varnishes (damar, mastic) can yellow over time.
Synthetic varnishes can discolor over time.
If you notice it, just remove and replace varnish.

There are also water and solvent-based varnish. Solvent-based varnish is a bit harder in use but also create stronger protection.

I use water-based removable Golden varnish.

Why varnish acrylic painting?

First of all, varnish is not mandatory but a recommended way to protect your acrylic painting. An alternative ways to varnishing are placing your painting under glass or leaving it without varnish.

Pissaro and Monet preferred the unvarnished look as many Impressionists

The reasons why varnish acrylic painting are numerous:

  1. Varnish protects the acrylic painting from dust and dirt.
  2. Varnish protects the painting from extremes of temperature or humidity and UV radiation
  3. Allows easy cleaning process.
  4. Varnish makes colors more vibrant and increases color saturation
  5. Varnish makes the surface even and creates that feeling of accomplished work.
  6. Varnish makes your painting last longer (dozens of years) due to removal options.

1 – Protection from the dust

During the drying process and even being fully dried, acrylic paint stay soft and allows dust and dirt to adhere to the painting surface.

As we remember, acrylics are water-based and the drying process is the simple process of water evaporation. When water evaporates, the other ingredients of the paint, such as agents and mostly binder (polymer) join together to form a film.

But while drying small pores appear. These micropores are very happy to collect dust. This is why varnish can save us – it creates a non-porous hard coat!

This is how much dirt can collect varnish over time. We can also see that it’s yellowing and why it is important both to apply and to remove and replace varnish when the time comes to protect and save our paintings for 100 years.

Pro Tip: 
Take photos and notes to know exactly when you varnished your painting and what varnish you used. 
When you will need to remove it, you will read the brand's instructions. 
Plus, looking at photos you can directly tell if it is time to replace the varnish.

If you choose to varnish your acrylic painting, you don’t have to put your painting under the glass. Painting without glass looks more natural and modern for me. I also don’t like the glare that glass gives while you look at the painting.

2 – Protection from the environment

A dried varnish is a hard protective layer, it is harder than cured acrylics which means it assures better protection.

  • extreme temperatures
  • extreme humidity
  • UV radiation

Remember the ideal environment for painting:

Temperature: 65-75 degrees Fahrenheit (18 – 24 C).
Humidity: 40-50%
Well-aired room

A hard varnish coat will protect the paint from drastic changes in temperature or humidity but it still doesn’t mean that you can store acrylic painting in an inappropriate environment.

Nowadays, varnishes contain Ultra Violet Light Stabilizers that disperse UV radiation before it hits the surface of a painting. Varnish prevents fading and yellowing of the paint.

The protective properties of the varnish are also useful for transportation. If your paintings are for sale or participate in exhibitions, varnish will protect them from light eventual damages.

3 – Cleaning

When an isolation coat and varnish are applied correctly, the painting will be able to be cleaned easily.

Just wipe the painting down. The surface is water resistant but don’t soak it with water 🙂

Without varnish cleaning can remove or damage the paint film.

4 – Gloss and color vivacity

Remember the perfectly clean white floor, and it seems bright, brand new, and glossy? Varnish does the same for your painting. Over time, this is a varnish that still makes your painting looks great, and colors – rich.

To assure the right level of the gloss, just mix matte and gloss finish or use directly gloss varnish.

The matting agent is white and sometimes will leave a milky finish to your paintings. Make sure you mix it properly.

Varnish creates a permanent enrichment to the colors. Even if you’ve just finished your painting and it looks great, fresh, and bright, acrylics will dry and lose a bit of their gloss.

You can use acrylic paint with more gloss like Winsor & Newton but only a varnish will make gloss and color saturation permanent.

Many artist, especially who work in photorealistic technique, rediscovered the beauty of their paintings after varnishing.

5 – Even and unified surface

Every brand and paint has different amount of binder and pigment in it. Some brands create low sheen or extreme sheen paint.

The amount of water you add to dilute paint will also affect its sheen.

Different acrylic mediums also have different shine rate. For example, you mixed paint with matte medium to create some objects and then used extreme sheen white. As the results we have uneven surface with areas with different shining.

Varnishing will smooth all these differences and create even and unified look, that we and other people will perceive as something finished and beautiful.

Varnish is the easiest and most effective way to make your acrylic painting look great!

6 – Longevity

Varnish is a key to make our creative heritage last longer. Once we finished our work we should think how to make sure it will live long life, especially if you create it for sale.

As we know varnish protects acrylic painting from dust, environment, enrich colors but also, we apply varnish first of all, to remove and replace it later. Such an irony, that something is useful because we can remove it!

Removing and replacing varnish can give your painting hundreds of years.

Before applying a varnish make sure you applied an isolation coat!

I need to mention that there is still a lot of artists who do not varnish their acrylic paintings at all. The oil tradition is ancient, but the acrylic one is considered young. We still don’t know what is the best way and adjust oil techniques to acrylic properties and logic.

It is your own decision, creative experiments, and knowledge that will suggest the best way. Varnishing a painting will protect it but also has some eventual negative effects which beginners will probably very happy to avoid.

If you are ready to varnish your painting:

You will need a flat separate brush, a clean jar or container, and a well-aired clean workplace.

You can use polymer Golden varnish, Liquitex varnish, Golden MSA varnish, or Grumbacher spray varnish.

The step-by-step guide for varnishinHow to Varnish an Acrylic Paintingg with a brush, with a spray, or how to remove varnish.