We recommend varnishing paintings unless you truly dislike the look. As discussed in our Studio Notes Newsletter on Modern Paints, unvarnished paintings are vulnerable to aging in ways that varnished paintings are not.
Oil painting mediums should not be used as a varnish or final coat. Picture varnishes should be colorless and removable. 1
Gamblin Gamvar saturates and gives greater depth to the colors in your painting and gives your work a unified and protective semi-gloss 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.
Gamblin Picture Varnishes from Gamblin Artists Colors on Vimeo.
When to varnish
For most paintings, there is no need to wait 6 to 12 months before varnishing with Gamvar. Gamvar can be applied when the thickest areas of your painting are thoroughly dry and firm to the touch. Gently press your fingernail into the thickest area of paint. If it is firm underneath the surface, then it is ready for varnishing.
To choose the size most appropriate for your needs, here is the approximate coverage:
- 4 fl oz: 80 square feet
- 8 fl oz: 160 square feet
- 16 fl oz: 320 square feet
There are several techniques to reduce the gloss of Gamvar:
- Dilute the varnish with additional solvent before using. The thinner the coating, the lower the gloss.
- Brush the varnish as it dries. When the varnish is starting to set up, if you continue to brush it then you will microscopically roughen the surface and it will be less glossy.
- Add Cold Wax Medium to the varnish.
If the varnished surface of a painting appears too glossy, you can apply a final coating of Cold Wax Medium. Rub on a thin layer of wax with a soft, lint-free cloth using small circular strokes. Allow the wax to dry completely for the highest degree of matte. To create a satin finish, allow the wax to dry 4 – 6 hours, then gently buff.
- Cold Wax Medium should be dissolved before adding to varnish. Dissolving approximately 10 -20% Gamblin Cold Wax Medium to 80-90% Gamvar will reduce the sheen by approximately 30%.
- First, add a small amount of varnish or Gamsol into the Cold Wax Medium with a palette knife to a slurry consistency. Then add the slurry to the larger volume of Gamvar.
- We recommend you matte only the amount of varnish you need. Apply the varnish/wax mixture to a test painting to make sure you have the correct level of sheen. Remember, you will not be able to judge the sheen until the varnish has dried.
1 The Painter's Handbook, Mark David Gottsegen