Should I varnish my oil painting or not? This is one of the most common questions asked by artists, and unfortunately, there’s no easy answer. In this blog post, we’ll explore the pros and cons of varnishing an oil painting, and offer some tips on how to achieve the best results. So whether you’re a beginner who’s just starting out or an experienced artist who’s looking for a little guidance, read on for all you need to know about varnishing your oil paintings.
Though some people argue you must varnish an oil painting to preserve and protect the paint, it is not a necessity. A fully cured oil painting dries to quite a hard surface and the oxidized oil creates a protective film over the pigment and is quite resistant to most liquids. If for whatever reason you believe you need to varnish your oil painting then you should be aware that it is more practical to purchase a varnish than to create your own. Making your own varnish can produce inconsistent results which may add to or detract from your finished oil painting.
Let’s explore this question a little more and you can decide in the end if you should varnish your oil painting.
What is varnish and what does it do for an oil painting?
Varnish is a clear, hard, protective finish or film that is typically applied to wood, metal, or other surfaces. Varnish can increase the durability of a painting and protect it from dirt, grease, stains, and scratches. It can also enhance the appearance of a painting by adding shine and depth.
There are different types of varnish, each with their own advantages and disadvantages. The most common type of varnish is made with a resin called damar. Damar varnish dries quickly, is durable, and provides a high-gloss finish. However, it can yellow over time and is difficult to remove once it has been applied.
Polyurethane varnish is another popular type of varnish. It is quite a new technology that came about in the 1970’s and it is made with a synthetic resin that dries to a hard, clear film. Polyurethane varnish is more durable than damar varnish and is less likely to yellow. However, it can be difficult to apply evenly and can be susceptible to bubbles.
Polyurethane varnish is also basically plastic, so you are coating an oil painting with a clear coat of plastic which can have unpredictable results over the years.
The benefits of varnishing your oil painting
The benefits of varnishing your oil painting are that it will protect the paint film from dirt and dust, and it will also protect the painting from UV light which can cause the colors to fade over time. Varnishing an oil painting can also give the painting a nice, even sheen.
The downside of varnishing an oil painting is that it can be difficult to remove if you ever want to make changes to the painting, and it can also yellow over time.
Another downside of varnishing is that it can make the painting look “flat” and lifeless, so it’s important to experiment with a small area of the painting before you commit to varnishing the whole thing.
What happens if you varnish an oil painting too early?
If you varnish an oil painting before it is completely dry, the varnish can become cloudy and may even cause the paint to peel. It’s important to wait at least 6 months after finishing the painting before you varnish it, and longer if possible.
Here are some of the problems you may encounter if you varnish an oil painting too early:
- The varnish can become cloudy
- The paint may start to peel
- The painting may develop a “bloom”.
If you’re not sure whether or not to varnish your painting, it’s always best to err on the side of caution and wait a bit longer before applying the varnish.
Should I use a matte or gloss varnish for oil painting?
This is a matter of personal preference. Matte varnish will give the painting a more muted look, while a gloss varnish will make the colors pop and create a more vibrant effect. The only thing I don’t like about gloss varnishes is that they can be a bit tricky to apply evenly. If you’re not careful, you may end up with brushstrokes in the varnish that will be visible once it dries.
A gloss varnish will also make it hard to view your oil painting from all angles, this can make photographing your painting a little harder than usual as the light will reflect off the surface at random points.
How to apply varnish – the dos and don’ts
When it comes to varnishing your oil painting, there are a few things you should keep in mind.
- First and foremost, make sure that your painting is completely dry before you start. If you try to varnish an oil painting that is even slightly wet, you run the risk of ruining the paint film.
- Once your painting is dry, you should also make sure that you are in a well-ventilated area. Varnish can be quite smelly, so it’s important to make sure you’re not going to be overwhelmed by the fumes.
- When you’re ready to start varnishing, use a soft brush (such as a sable brush) to apply a thin, even layer of varnish to the surface of your painting. Start in the middle and work your way outwards, being careful not to overbrush or leave any brushstrokes visible. Once you’ve applied the first layer of varnish, wait for it to dry completely before applying a second layer.
- Make sure that you’re using a varnish specifically designed for oil paintings. There are many different types of varnish on the market, but not all of them will work well with oil paint.
- Apply varnish in a corner of the painting if you have never tried the brand or type before. This is called a spot test and it will ensure you don’t mess up your entire painting.
- If you are using a spray varnish, make sure to do it in a well-ventilated area and that you apply a light mist from left to right (or light to left) and avoid applying the spray varnish to one specific spot or too close to the surface. This will cause the varnish to be applied too thickly in one area, making it appear too glossy and it will also make the varnish run.
- Don’t rush the process, let each coat dry before you apply the next coat of varnish.
Should I varnish my oil painting – Final thoughts
Should I varnish my oil painting is a difficult question to answer definitively because there are pros and cons to each type of varnish. Ultimately, the decision of whether or not to varnish your painting should be based on your personal preferences and the desired outcome for your painting. If you want a natural look for your painting, you may choose not to varnish it. If you want a more protective finish, you may choose to varnish your painting. Experiment with different types of varnishes and see what works best for you and your artwork.
My personal preference is to not varnish an oil painting, the only time I do varnish one is for aesthetic reasons because I have some areas that look matte and some areas that look shiny. I will apply a varnish to give the entire painted surface an even sheen.
If you think you’ve ruined your oil painting with varnish then have a look at this post here!

Sources
Cover image “Magic Wings” by Rusty Clark ~ 100K Photos is licensed under CC BY 2.0.