How to varnish an acrylic painting

The varnish is the final step for painting. It protects acrylic painting for years from all negative factors and make it just even more beautiful.

How to varnish an acrylic painting

Varnishing an acrylic painting is easy. Choose your varnish, I use Golden Polymer removable varnish. Use a separate brush or a spray, thin the varnish if needed, apply it evenly and let it dry. Make sure you applied an isolation coat before varnishing.

As I said, the process is quite simple, but there are still some precautions. You also may want to choose a different type of varnish, that’s why I decided to share with you all I know about varnishing, but also how to safely remove and replace varnish when the time comes.

Table of content:

  1. What is varnish?
  2. How to varnish an acrylic painting
  3. How to remove varnish from acrylic painting
  4. What type of varnish to choose?
  5. Best varnish for acrylic painting
  6. Why varnish acrylic painting?

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What is varnishing?

A varnish – is a clear transparent protective coat for applying on diverse surfaces to form a hard, clear, shiny surface when dry.

Varnishing an acrylic painting means covering a finished and completely dried ( ±24 hrs.) painting with special varnish (liquid resin) to protect your acrylic painting.

Any surface like canvas, paper, metal, plexiglass, or wood can be varnished.


How to varnish an acrylic painting

The varnish is the final step while painting. You are almost done! In general, I use a separate brush for varnishing, but sometimes I create a textured surface that is very difficult to evenly cover with a brush. In this case, I use spray.

With spraying it is also easier to avoid brush strokes and bubbles.

I’ll share with you both methods and also, How to remove varnish steps too.

  1. How to varnish an acrylic painting with a brush
  2. How to varnish an acrylic painting with a spray
  3. How to remove varnish from an acrylic painting
Pro tip: If you need a photo of your painting, make it before varnishing!

Always test your varnish first. Varnishing can have unexpected results such as cloudy finish.

Once you finished your painting, wait 1-2 days until it fully dried. Apply an isolation coat. Wait for 24 hrs. and move on to varnishing.
If you are using the impasto technique, it’s recommended to wait 1-2 weeks before applying the isolating coat or varnishing.

How to varnish an acrylic painting with a brush

Time needed: 2 hours.

  1. Check that you’ve applied isolation coat and it is fully dried

    If no, go for it now, here is the full process

  2. Clean the surface

    Wipe the painting with a lint-free cloth.

  3. Prepare the workplace

    Choose a dust-free room. The painting should be on the horizontal. A vertical application can lead to drips. Place it on cups or wooden sticks to make sure it will not stick to table or floor. This way you can reach all sides.

  4. Pick your brush

    It should be a separate brush that you use ONLY for varnishing. I prefer wider brush. There are some special varnish brush too, but you can just pick any smooth, good quality wide brush.

  5. Take a clean shallow container

    Poor varnish in it. If you mix your varnish before application, mix a bit more to make sure you have enough.
    Unused varnish can be good for another couple of days, after it, you will find it cloudy.

  6. Apply the varnish

    Work quickly with no extra pressure, move the brush at an angle from the top to the bottom and from one side to another. Try to apply in even strokes. You can slightly overlap each stroke.
    1-3 thin coats are enough. Check the surface from an angle to make sure there is no uncovered areas.
    DO NOT go back over areas you’ve just gone over.

  7. Let it dry

    Make sure there is no dust.
    You can place the painting against the wall or cover it (not with plastic!) to prevent dust collection.
    The varnish dries to touch in 30 minutes. If you need another coat of varnish, wait at least 24 hours and apply it in strokes that are perpendicular to the previous coat.

  8. Clean brush, container and workplace


How to varnish an acrylic painting with a spray

  1. Check that you’ve applied an isolation coat and it is fully dried and clean (wipe the painting with a lint-free cloth.)
  2. Wipe the painting with a lint-free cloth.
  3. Choose a dust-free room. The painting should be on the vertical (contrary to the brush application!).
  4. Shake the spray very well, it affects how even the finish will be. Check the nozzle, it should be clean
  5. Apply the spray at least 30 cm away from the surface. While spraying, often check the nozzle.
  6. Spray the sides.
  7. Let it dry. Make sure there is no dust. You can place the painting against the wall or cover it (not with plastic!) to prevent dust collection. The varnish dries to touch in 30 minutes. If you need another coat of varnish, wait at least 24 hours and apply it.

How to remove varnish from an acrylic painting

To protect your painting and remove eventual dust and yellowing you will need to remove the varnish. You will absolutely need an isolation coat for this and if you skipped it before, varnish removal can significantly damage the paint.

Step-by-step varnish removal:

  1. Get ammonia. It is the most common varnish removal but double check your varnish brand instructions.
  2. Work in a dust-free, well-aired area.
  3. Wear latex gloves, a dual filter respirator, and splash goggles.
  4. Place your painting horizontally.
  5. Get a lint-free, soft, white cloth and saturate it with ammonia.
  6. Test the solvent on a small area of the painting.
  7. Put the cloth over an area of the painting. Cover the area with a plastic sheet to reduce evaporation. Leave it for 2-5 min.
  8. Rub the cloth gently until the varnish starts to dissolve.
  9. Repeat until the entire area is cleaned.
  10. Let the painting dry.
  11. Apply the new varnish.
If you see any paint color on the cloth, stop right away and allow the surface to dry!

Best varnishes

BrandNotePrice
Golden Polymer VarnishRemovable water-based varnish with Ultra Violet Light Stabilizers
Not recommended for use on furniture
Thin with 25% distilled water before use
Remove with ammonia
4 oz – 128 oz
$6.83 – $84.41
Golden MSA varnishMineral Spirit Acrylic Varnish with UltraViolet Light Stabilizers
Removable
Thicker viscosity than traditional varnishes
Remove with spirits
4 oz – 128 oz
$14.69 – $111.65
Liquitex VarnishUV protection, durable
NOT removable
Matte, Satin, Gloss, High Gloss
* I got some testimonials about cracks and uneven coverage using Liquitex.
$6.92 – $90.88
Grumbacher spray varnishCrystal-clear when applied
Dries quickly
Has gloss finish
Non-yellowing
Removable with paint thinner or a mild solvent
11 oz
$11.42

What type of varnish to choose?

Varnishes vary based on:

  1. removal option: removable and permanent
  2. finish: gloss, satin, matte
  3. composition: water-based or solvent-based.

Brr…what to choose? I choose removable gloss or satin polymer varnish – Golden Polymer Varnish. To make your own choice, feel free to dig in:

Varnish can be removable and non-removable (permanent)

Basically, you need to remove and repeat varnishing every 50 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 soften the colors and looks semi-gloss;
  • Matte varnish may make darker colors lighter. Matte finish is not reflective.

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

If you try to apply a satin or matte varnish to a black painting, the black color will look duller. To create real dark black, use a glossy finish.

The choice of matte/gloss varnish can also rely on the lights and environment where the painting will be placed. Remember that a glossy finish is light reflective so it can cause a glare, while a matte finish is non-reflective.

Varnish can be water or solvent-based
  • The water-based varnish is an acrylic polymer. It is the best choice for beginners (and for most pros too). It protects the painting, doesn’t have a strong smell, dries quickly.

The water-based varnish can be less convenient for big canvases as it dries quickly. It’s worth saying that it is a bit milky while applying, but dries clear, don’t worry!

The recommended polymer varnish is Golden Polymer Varnish. They need to be thinned at 3:1 (varnish to distilled water) before applying.

  • The solvent-based varnish or Mineral Spirit Acrylic (MSA) varnish dry harder than water-based varnish.

MSA varnishes are clear when wet, and have self-leveling qualities, it means you don’t have to worry about brush strokes. They are a little bit more clear when dried than water-based.

Solvent-based varnish needs to be thinned before using with full-strength spirits. It smells pretty strong and not easy to clean after.

Golden MSA Varnish may be a good choice for you, and here is brand’s official How to thin video:

Precautions:
Natural varnishes (damar, mastic) can yellow over time.
Synthetic varnishes can discolor over time.
If you notice it, just remove and replace 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 cured, acrylic paint stay soft and allows dust to adhere to the painted areas.

As we know, acrylic paint is water-based and the drying process is the process of water evaporation. When water evaporates, the other ingredients of the paint join together to form a solid film.

This is when micropores appear and the dust can easily stick to them. The varnish creates a non-porous hard film and protects the painting!

You can see how much dirt can collect varnish over time and you don’t apply it, all of it will stick to your acrylic paint and there will be no ways to clean it. The yellowing can also happen and this is also why it is important to apply and to remove and replace varnish on regular basis (but not too often).

Pro Tip: 
Take photos and make notes about the date and varnishing methods or product. 
When you will need to remove it, you will follow the brand's instructions. 
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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.