Retouch varnish provides a temporary protective layer over an oil painting, restoring the gloss.
In this guide, we’ll cover what retouch varnish is, how and when to use it. We’ll also review the best brands of retouch varnish, the advantages of using it and how it compares to oiling out. We’ll also cover the point of whether retouch varnish is really needed. So you can decide whether to include the step in your oil painting practice.
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What is retouch varnish?
Retouch varnish is a thinner version of damar varnish that can be used as a temporary protective layer on recently finished oil paintings. It helps to fill up the porous film of oil paint. This allows oil paint to dry over a longer period while still protecting the painting from dust and dirt. Retouch varnish also repairs any sunken-in areas in the paint film and restores the gloss.
Varnish improves the appearance of a finished artwork, restoring the true tones and values of dark colours. When an oil painting has dried, areas of the painting can look matte or dull due to the oil layers having sunken into previous layers. Retouch varnish resolves this issue.
Why apply retouch varnish before damar resin varnish?
The reason artists use retouch varnish is to protect their painting against the elements, giving it an even surface finish before the painting is able to be varnished with damar resin.
The final layer of damar resin varnish should only be applied once the painting has fully dried and cured. Oil paints can take six months or even a year for them to fully dry and cure, depending on the thickness of the paint. This means that artists need to wait a long time before fully protecting their artwork with damar resin.
However, retouch varnish can be applied when the painting is touch dry. So it serves as a temporary protective measure. It’s important to read the instructions of the specific varnish you have, as directions can vary between brands and formulas.
Use cases of retouch varnish
- To use as a protective layer when the painting is touch dry, before using damar resin varnish.
- Many artists who need a newly completed painting to look ready and freshly varnished for a gallery show will use retouch varnish as a temporary measure before varnishing, if they do not have time to wait for it to cure before the final layer.
- For artists who use damar or resin based varnish, not Gamvar.
Do you need to use retouch varnish?
No, you do not need to use retouch varnish when applying Gamvar.
Gamvar is a picture varnish specifically designed for oil paintings that can be applied full strength after the painting is dry to the touch. This means that retouch varnish is only necessary to use as a temporary protective layer before using damar varnish. The great thing about Gamvar is that it can be applied immediately after the painting has dried, so there’s no need to wait for oxidation or any other process. Additionally, Gamvar is breathable which allows it to be applied when the paint is firm and dry to the touch.
When applying Gamvar, it’s important to use a very thin layer with a bristle brush. This will help break up any bubbles and ensure an even coat of varnish.
Overall, Gamvar is an easy-to-use picture varnish for oil painters that doesn’t require retouch varnish prior to application. Artists can opt to oil out a painting to resaturate sunken in areas before varnishing, but retouch varnish is not necessary when using synthetic varnish.
More and more contemporary oil painters are choosing to use Gamvar, due to the quickness with which the varnishing process can be completed.
If you want to learn how to varnish a painting using Gamvar, read our guide.
How to apply retouch varnish
If you choose to use retouch varnish, it’s important to make sure that all colours are completely dry before you begin. If any colour is not completely dry, then turpentine in the retouch varnish can cause smearing. The best way to apply retouch varnish is by spraying it onto your painting from a distance of at least 12 inches away. This will ensure that you get an even coverage without any drips or runs. If using a spray varnish, make sure to work in a fully ventilated room, with two open windows where air can circulate. Ideally, spray varnish should be applied outside.
Apply liquid varnish with a wide hog brush, or synthetic alternative to a dry painting. The room should not be too hot, or humid. Retouch varnish should be used very sparingly, in a thin layer.
The best brands of retouch varnish
When choosing a brand of retouch varnish, look for one that contains natural resins such as damar resin or ketone resin. These resins provide superior protection against UV rays and help keep your painting looking its best for around six to nine months, until the painting is ready for its final varnish coat. Some popular brands include Old Holland Retouch Varnish and Royal Talens Retouching Varnish.
Retouching varnish vs oiling out
Oiling out, is a method which involves mixing solvents with oils and then applying to create an even finish. The oil layer acts to saturate areas of the paint that has sunk in due to faster drying metal based colours. By saturating these areas with oil, it adds gloss and therefore creates the appearance of depth and intensifies shadows. It also works to strengthen areas of the painting that have sunk in.
A final glaze layer of linseed oil, which can be thinned with spirits is a good way to reunify the colours of the artwork before varnishing. However, it will not protect the painting from UV, dust or dirt. Retouch varnish on the other hand can act as a removable protective layer for conservation purposes.
After oiling out, the final layer should take a week or two to feel dry to the touch, so it can be a lengthy process.
These two methods can be used in conjunction with each other to create an even surface finish after varnishing. If you see any dull or sunken in areas of your painting, which might be visible in areas where you have used umber pigments, consider creating a final glaze layer by oiling out. Then you can apply retouch varnish to protect the painting from UV, dust and other pollutants once the glaze layer has dried. The retouch varnish will sit on top of the glazed painting, with an even surface finish.
Retouch varnish vs damar varnish
Damar resin varnish and retouch varnish are both used to add a protective coating over oil paintings, but there are some key differences between the two.
Retouch varnish is usually applied to a touch dry painting as a temporary layer of protection. It helps preserve the colours and texture while they are still curing, while also providing a barrier against dust and dirt.
Damar resin varnish, on the other hand, is generally applied when the painting has been fully dried and cured for at least six months. This type of varnish is much harder and more durable than retouch varnish, making it ideal for preserving artwork for long-term storage or exhibition purposes. It should always be applied in several thin layers that can then be removed or adjusted with solvents if need be.
In summary, retouch varnish can be used as soon as the paint layer has dried to protect against dirt and fading backlit colours, while damar resin varnish provides long-term protection for oil paintings that will last for many years with minimal adjustments or maintenance needed.
How long does retouch varnish take to dry?
Retouch varnish can take anywhere from a few hours to a few days to dry, depending on the brand and thickness of your application. Generally, it’s best to wait at least 3-4 days before adding any additional coats. That said, some types of retouch varnishes can take even longer to dry, so it’s important to read the instructions on your particular product carefully before beginning your project.
Applying varnish after retouch varnish
Applying damar varnish after retouch varnish is an essential part of the oil painting process, when using these two products (instead of Gamvar). Retouch varnish helps to protect the paint layer while it is drying, but a permanent and protective final varnish coat should be applied only when the painting has fully oxidised. This means waiting for the painting to cure, which can take around six months or a year.
Before applying varnish, make sure that your paint layer is completely dry and free from any dust or dirt particles. The canvas may also need to be cleaned with a lint-free cloth in order to remove any residual oils from the surface before applying the varnish coat. Then, simply brush on a thin even layer of varnish in long strokes starting from the top of your painting and working downwards in one direction only. Once this first coat has been applied, wait at least 2-3 days before adding additional coats if desired.
In conclusion, retouch varnishes are a reliable way for artists to protect their artwork from dust and UV while still allowing them plenty of time for curing.
However, with the introduction of synthetic varnishes like Gamvar, there is now little need for applying retouch varnish, then waiting for the painting to cure to apply damar resin. Artists now have the option of simply applying Gamvar when the painting is touch dry, as the final step.