Three Reasons to Varnish Oil Paintings

Three Reasons to Varnish Oil Paintings

with 18 Comments

I was recently in a friend’s home and noticed a large oil painting on his wall. The surface sheen of the canvas was very uneven. Some areas of the painting were glossy and others were matte. When I asked my friend if he would like some help applying a coat of varnish he told me he assumed the painting was supposed to look like that. It was the perfect time to explain the three reasons to varnish oil paintings.

Three Reasons to Varnish Oil Paintings
  1. To protect the surface
  2. To create an even sheen (glossy or matte)
  3. To revive the saturation of colors that have become dull due to the drying process

#1 is definitely the most important reason to varnish an oil painting. Dust and grime can accumulate on the surface of paintings over time, especially if a painting hangs in a smoky environment. The protective layer of varnish can be removed to restore the painting to its original look. But you have to be sure to use a removable varnish.

The #2 reason is what alerted me that my friend’s painting needed varnish. As an oil painting dries, the surface may not end up with a uniform sheen. Sometimes this is caused by the pigment mixtures themselves and whether any mediums were used. Other times it depends on whether all parts of the painting were allowed to dry at the same rate. Either way, a varnish layer will bring the surface of the painting to an even sheen.

Reason #3 has to do mainly with color. Even if the painting dries to a uniform sheen, sometimes certain colors will end up looking duller than they did when they were wet. You may notice this effect in areas painted with dark earth tones like burnt umber. In artist jargon we might say that the color dried “flat.” A coat of varnish can bring back the saturation of these flat colors.

Gamvar Varnish Bottle

Recommended Varnish

Now that we know the reasons to varnish, how do we go about choosing a varnish? As I mentioned already, be sure to look for a removable varnish. I think it’s also important to choose a varnish that doesn’t change color. (Widely-used varnishes made from tree resins like dammar can yellow and darken over time. As you might know, I do my best to avoid materials that cause yellowing.)

In the 1990s, Robert Gamblin collaborated with the National Gallery of Art in Washington DC to create a better varnish for artists and conservators. The result is Gamvar Picture Varnish. Gamvar is removable with mineral spirits and Gamblin claims that it will stay water-clear over time. You can even pick your desired sheen with gloss, satin and matte versions available. I’m partial to the matte look myself.

Have something to add about reasons to varnish? Leave a comment below!

18 Responses

  1. Virginia Beale
    | Reply

    Thanks Dan! I am always looking for a good matte varnish…. does this one require the painting be at least six months dry before applying? That has been my experience so far with varnishes.

    • Dan Schultz
      | Reply

      According to Gamblin’s website: “Gamvar may be brush applied when the painting is dry to the touch and firm in its thickest areas. For some oil paintings, that may be two weeks, for others, 2 months. To check if it’s dry, gently press your nail into the thickest part of your painting.”

  2. Tina Jalalian
    | Reply

    Thank You Dan! Very helpful Info. Cant wait to Varnish my paintings 🙂

  3. Diane
    | Reply

    Thanks very helpful. If the painting is 8 years old is it too late to varnish?

    • Dan Schultz
      | Reply

      As far as I know, it would be totally fine to varnish an 8-year-old painting. You might want to gently wipe the surface of the painting first though, to remove any dust, etc.

  4. Liz Todd
    | Reply

    Hi Dan,
    Any thoughts about using Retouch Varnish ? I often use this when part way through a painting and want to even out the
    surface. It also allows me to paint, then wipe out if I don’t like the added touches.
    Thanks !
    Liz

    • Dan Schultz
      | Reply

      I’ve used retouch varnish in the past, but the kind I used was made with dammar resin which has a tendency to yellow over time. So I have been avoiding it. Plus, I don’t really like having too many layers in a painting because I want to be sure the paint itself can easily bond and not be separated by varnish layers in between. Does that make sense? I bet a web search would lead you to more info about using retouch though. You might be able to find more in-depth advice on it….

      • Liz Todd
        | Reply

        Thank you for the feedback Dan. Interesting to know. So many learning curves. Happy holidays !

  5. Scott Gellatly
    | Reply

    Nice article, Dan! Thanks for the shout-out!
    Cheers,
    Scott

  6. Scott Dienhart
    | Reply

    I have always struggled with varnish a crucial step in the success in a painting. I have not had much luck with Gamvar but I have not tried the newly released matte and satin finishes. Anything important that I may be missing on the application process?

  7. Andy Fulton
    | Reply

    Dan, I paint with water based oil. Does varnish work ok with these water based oils?

    • Dan Schultz
      | Reply

      I don’t have much experience with water-mixable oils. You’ll have to do some research and see what you can find out. I’d appreciate a comment here if you do find some good advice on that.

  8. Andy Fulton
    | Reply

    Dan, my first step was with a knowledgeable fellow at the San Clemente Art Supply store. He said no don’t varnish my water based oils. But I will look further and let you know. Thanks, Andy

  9. Tricia hillenburg
    | Reply

    Does the gamvar varnish work well with walnut oil paints and mediums. I’ve had some painting parts in the past that have had beading (where the varnish avoided certain areas) and I’m not sure what caused it. I don’t remember what I was using at the time. Thanks

    • Dan Schultz
      | Reply

      Hmm I’ve never had problems with Gamvar beading up. I use M. Graham oils (made with walnut oil) all the time. Not sure what might have caused that result for you.

  10. Lee Edwards
    | Reply

    I too am partial to Gamvar Matte finish. It seals in the colors but doesn’t cause reflected glare like the glossy. One issue that has come up: when the varnish dries I can see some lap lines where the brush strokes overlapped. Typically I’ll brush back and forth horizontally on the canvas which is flat on a table, using a cheap 2″ nylon brush that can be discarded. I see from the Gamlin demonstration video they recommend a scrubbing type of brush work in multiple directions. One artist has recommended I simply use a soft cloth to apply the varnish without brushing. What do you recommend?

    • Dan Schultz
      | Reply

      I apply the varnish as Gamblin recommends — I use a cheap synthetic brush with a scrubbing motion. I also try to keep from applying the varnish too thickly.

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