Oil paintings take up to 24 hours to dry and cure, and most times even longer to fully cure with thicker layers of paint or drying conditions that are not ideal.
Keeping that in mind, you do not want to add varnish to your oil painting before it is fully cured.
Adding your varnish too early can do a few things.
First, some varnishes do have solvents in them that can damage uncured paint, it can remove the paint from the canvas and damage the painting composition itself, and it can damage the canvas as well.
It is helpful to first take a look at what varnish does for an oil painting.
Varnish creates a layer of protection for the oil painting.
Oil paintings can collect dust and grime very easily which can change the overall look of the painting and can affect the coloring of the painting.
Varnish is going to protect the painting so that it can be cleaned later on if need be, and so that it can remain vibrant no matter what.
Second, if you add varnish too early the varnish does have the potential to penetrate and disturb the top layer of the painting and become part of the paint.
This means that if you do need to remove the varnish later, it may be impossible to do so without changing the painting itself or potentially damaging the painting.
How Long Should You Wait?
There is a general rule that six months from the time of completion is an acceptable time to wait before adding any varnish to the painting. Though it is meant to protect, adding it too soon can cause major issues. Waiting six months gives the painting time to fully and wholly dry.
There are different stages of dryness for oil paintings, you want to wait for the hard dry to take place before you add the varnish.
Hard dry means that the paint is fully cured, that it is not budging and that it is totally dry through and through.
This is going to prevent the possibility of any solvent in the varnish from integrating into the paint and damaging or changing the painting in any way.
If you cannot wait the full six months and need to varnish sooner, there is a test that you can perform to determine if the paint is dry hard.
It is called the fingernail test. You may want to wear gloves or use some sort of covering on the thumbnail and press the nail into the painting with slight downward pressure.
You then want to take a soft cloth and buff the area to remove the nail mark, if there is one.
If you can buff the nail mark out it means that the paint is fully cured and ready to be varnished.
With very thin paintings or those that do not use a ton of layers or very thick paint, you may be able to varnish before the six-month mark.
Choosing the Right Varnish
With any oil painting, the varnish that you choose is as important as the painting itself. There are a few different factors to consider when choosing varnish:
- Transparency and color change – do you want a varnish that is fully transparent and that does not change color, or does it matter if the varnish slightly changes color over time?
- Elasticity – some varnish does dry down very hard and does not allow for much movement, you need to look for a varnish that protects, but that remains elastic.
- Protection – a varnish is meant to protect the painting. You want a varnish that is going to provide mechanical protection or physical protection of the painting from things like dust, grime, and other buildups.
- Removable – you want a varnish that is going to be removable if need be. You want something gentle that contains a nonpolar solvent that is not going to damage the painting.
There are so many varnish options out there. Taking the time to find the one that is going to work for you and your painting is a must and can make a huge difference overall.
Varnish is a must with oil paintings, waiting long enough to apply is going to protect your painting and allow the varnish to do its job.
I hope this article was helpful in understanding the consequences of varnishing an oil painting too early.
It is important to allow the paint to dry completely before applying a varnish, or you may end up with a cloudy or streaky finish.
The good news is that there are many different types of varnishes available on the market, so you can choose the one that best suits your needs.
Joseph Colella (Joe Colella) is an Editor and Writer at WastedTalentInc. As a frustrated artist with over 40 years experience making art (who moonlights as a certified Business Analyst with over 20 years of experience in tech). While Joseph holds a Diploma in Information Technology, in true wasted talent fashion he spent years applying for various Art degrees; from the Accademia di Belle Arti (Napoli), to failing to get into the Bachelor of Arts (Fine Arts) at the University of Western Sydney. While he jokes about his failures at gaining formal art qualifications, as a self-taught artist he has had a fruitful career in business, technology and the arts. His goal is to attend the Julian Ashton School of Art at The Rocks Sydney when he retires from full time work. Joseph’s art has been sold to private collectors all over the world from the USA, Europe and Australasia. He is a trusted source for reliable art advice and tutorials to copyright/fair use advice and is committed to helping his readers make informed decisions about making them a better artist.
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