Thoughts on Varnish from a Conservator
Written by Amber Smith Schabdach, Senior Paintings Conservator
Varnish brushes
Varnishes in our laboratory
Varnish removal is one of the most common steps undertaken during a painting treatment. While it is common, it is uniquely challenging, and is often the step that untrained people end up damaging the paint layer. Varnishes vary in solubility and often the paint layer will dictate what is safe to use to remove the varnish itself.
Abraded paint
Abraded high points of paint
Reasons to varnish:
Many artists varnish their paintings in order to provide a protective coat, but it can also alter sheen and saturate colors. Varnish protects the paint layer from dust and grime, but can also protect against UV light fading if the varnish has an UV absorber in it.
Reasons to remove varnish:
Varnish is traditionally a “sacrificial” layer that is applied in the knowledge that it will age, and fail over time. It often becomes yellow or gray as it ages, obscuring the true colors of the paint layer, or can crack or fracture, causing a lack of protection for the paint. Additionally, when a varnish ages, it can become foggy or opaque when viewed under UV light, making it difficult for conservators to determine the amount of retouching present. When this happens, it is time to remove it!
Half-cleaned, yellowed varnish
Opaque varnish under UV light
Factors to consider when re-varnishing a painting:
As conservators, we only re-varnish paintings that came in with a varnish layer. We respect that if it came in unvarnished, than most likely that was the intent of the artist. When choosing a varnish, we tend to choose from a variety of synthetic resins, such as Regalrez, that last longer than their natural counterparts, such as dammar. We think about the level of gloss desired, saturation of the paint layer, the environment it will live in, the protection desired, and of course, the reversibility.
Detail of an unvarnished piece by Joan Mitchell, Chord II, courtesy of The Tate and The Estate of Joan Mitchell
Final Thoughts:
Varnishes play a big role in how a painting appears. The removal of a discolored varnish can significantly improve the readability of an image. Varnishes also provide a great protective layer that makes it easier for conservators to remove grime and soot. Choosing an appropriate varnish for each painting is almost the same as applying make-up- it should not be the first thing noticed, but it should compliment the beauty of the whole image.
Before varnish removal
During varnish removal
After treatment and re-varnishing
Photo Source:
https://www.tate.org.uk/about-us/projects/cleaning-modern-oil-paints-0/trouble-modern-oils
