Once in a while I come across a product that makes life in the studio so much easier that I feel compelled to share it with readers. I am not an employee of Gamblin, nor do I receive any compensation for this review.
Once a painting is done, the oil painter faces two vexing questions: should I varnish the painting and, if so, how should I varnish it? The “why” of varnishing is not the primary subject of this article, but for those who are interested, please see Why Varnish at the end. The “how” of varnishing, though, is more problematic. There are many different types of varnishes and brands and applying any of them incorrectly can easily ruin a painting.
I recently tried Gamvar picture varnish from Gamblin Artist’s Oil Colors. With just a little testing, I could see that I had found a varnish that solved my most difficult varnishing problems:
1. It can be applied much sooner than traditional varnishes
An oil painting goes through a curing process that continues long after it feels dry to the touch. So as not to interfere with this drying process, it is usually recommended that you wait six months (for thin paint) to a year (for thicker paint) before varnishing. This is a real problem for painters who must release their work to buyers or galleries sooner than that. The Gamvar formula is permeable enough to allow the underlying oil paint to proceed with its natural curing process, so you can apply the varnish once the paint is dry. What’s more, the solvent component of Gamvar is mild enough so it won’t dissolve the thin glaze layers of the painting. Gamblin notes, “How do you tell if a painting is ready to varnish? It’s easy — just touch it. If there are impasto areas, gently press your fingernail into that impasto. If it is firm underneath the surface of the painting then it is ready for varnishing [with Gamvar].”
2. It is easy to apply
Gamvar is very thin and non-oily, so it can easily be applied in an even, thin coat. This is good news. Some brush-on varnishes are oilier and slightly viscous, making it harder to achieve an even coat. Spray varnishes can be very effective, but they require protective masks and a dedicated spray area.
3. It permits control of the surface sheen from glossy to matte
One of the benefits of varnishing is that it enables painters to adjust the surface sheen of the painting after it is done. It can also correct or reduce flat (matt) spots. Gamvar is available in gloss (original), satin, and matte formulas. With the addition of Gamvar Matte to the lineup, adding cold wax medium to the gloss formula is no longer necessary.
Gamvar also offers another advantage. It can be removed with Gamsol, a very mild solvent. Damar varnish can only be removed with a strong solvent such as turpentine. Being able to remove a varnish with a mild solvent means less risk of damaging the delicate paint layers.
Although Gamvar is easy to use, you should test it on an old painting first, as you would any new studio method. Gamvar naturally creates a gloss sheen. If you want a satin or matte finish, you will need add cold wax medium.
Shelf life: I am often asked how long Gamvar lasts. Scott Gellatly, product development manager at Gamblin, writes: “Gamvar does not have a specific shelf life, compared to other varnishes. As the case with all varnishes, however, they are best used as fresh as possible. Painters should buy the size container that is appropriate for their needs and use it within a year or two. Here is the approximate coverage for each size we now make available:
4.2 fl oz: 80 square feet
8.5 fl oz: 160 square feet
16.9 fl oz: 320 square feet
Avoiding streaks: If you are getting streaks you are almost certainly applying too much varnish. Always apply varnish as thinly as possible, avoiding visible brush strokes. Those new to varnishing overestimate the amount of varnish necessary and apply far too much. Imagine that you are trying spread the varnish as far as it can go.
When a painting’s surface is more textured, say, from a coarse-weave canvas or the texture of the strokes themselves, streaking will be less noticeable. However, the potential for streaks is greater when the surface of the painting is very smooth and the paint is applied very thinly with little or no visible texture. Then there is no texture to interrupt or camouflage the streaks.
Immediately after applying a very thin layer of varnish, I use a very soft, delicate, “fluffy” brush and lightly dab the surface. This breaks up the streaks. Use a quick, but light up and down dabbing motion, and pay close attention that you don’t miss any spots. The brush shown here (above) is a 2-1/2 inch wide Asian-style Hake wash brush with sheep hair. Note: It is preferable to not use the same brush for this dabbing step as you did for the varnishing. The varnishing brush is laden with wet varnish; its hairs will be clumped together and have less “fluffiness.” Use a dry brush with hairs that are still fluffy and open. If you must use the same brush as you used for varnishing, wipe it back and forth on a roll of paper towels until most of the remaining varnish has been soaked up and the bristles have opened again and regained some of their fluffiness.
From the Gamblin website: “Gamvar Picture Varnish saturates colors in your painting and gives your work a unified and protective surface. Developed in collaboration with the National Gallery of Art, Gamvar goes on water-clear, stays water-clear and can be easily and safely removed with Gamsol. Gamvar is virtually odorless and ready to apply. Brush apply. Do not spray. All Gamvar can be applied when the thickest areas of your painting are thoroughly dry and firm to the touch. Please visit our Video Demos page for additional information.”
Why varnish? Painters varnish their work for two reasons. First, it is a way to control the surface sheen of the painting once it is finished. Second, a varnish serves as a protective coating. A painting, like the walls in your house, becomes dirty over time. Or worse, if there is smoke damage or the painting were accidentally splattered with a foreign substance, the varnish is what would be affected, not the paint itself. If you try to remove a foreign substance from an unvarnished painting, you risk damaging the paint surface. But when you remove a foreign substance from a varnished painting, you are only removing the varnish, and are able to preserve the integrity of the paint surface. Then, a new varnish can be applied. Needless to say, varnishing won’t protect the painting from mechanical damage. If your cat uses it as a scratching post (this really happened to me), varnish will not help!