Should I varnish my paint? … What’s the point in doing so?
Many of my students have asked about paint varnishes. I will explain the reasons for using a varnish, some good practices to base your work on and than you can decide for yourself if varnishing seems like a good option for you. If you are newer to painting, a varnish is an extra layer that goes on last, it is applied over the completed painting and therefore must be clear. Varnishes come in glossy versions, matte or anywhere in between.
There are three benefits to varnishing a painting:
- Varnish helps protect the painting underneath
- Varnish unifies the final surface sheen
- Varnish saturates the colors beneath
All paintings are susceptible to the damages caused by natural and sometimes not so natural elements over time. These forces can act quickly such as in the case of a sharp object scratching across the painting’s surface. Forces can also inflict their damages slowly such as in the case of dust, dirt, and smoke build-up on the painting’s surface and the damaging effects of prolonged light exposure in general. A varnish adds an extra barrier, almost like an insurance policy that protects the painting below it. If one inadvertently scratches the painting, it is the varnish that is damaged and not the painting itself. When dirt, soot, and other particles collect or even bond with the surface of the painting, they are doing so to the varnish, not the paint beneath it. If applied correctly using the correct type of varnish, this varnish can eventually be removed and reapplied revealing a like-new painted each time!
Any painter of oils or even acrylics can tell you that certain paints have more sheens than others. Because all pigments have their own unique set of properties they are all used in varying amounts in each tube of paint. Sometimes things are added to the paint to stabilize the blend, and often different amounts of the vehicle (oil or acrylic polymer) are used. This ultimately creates a sheen, or glossiness disparity between the different tubes of paints when used. How you thin your colors and doctor them up using various mediums also affects the final outcome. A finished painting with a high degree of sheen disparity can be distracting to viewers. A varnish can unify the entire painting’s surface by making the entire painting the same caliber of glossiness. The artist can chose to make the painting appear to have a near-matte finish, extremely glossy, or somewhere in the middle.
A glossy varnish restores saturation to the colored areas of paint that lay beneath it. Often artists create a painting and formulate their judgments regarding color, based upon the wet paint they are using at that time. Once the paint dries it can look different than the artist had intended. Leaving the studio happy, painters sometimes arrive the next day, after the paint has dried, thinking “that area looked better yesterday”. Many artists refer to their color as becoming “dead” or “lifeless” especially the earth tones they use, such as the siennas, umbers, and ochres. If you would like to add some saturation to your colors and make your painting look the way it did while it was wet with paint, a varnish is your answer.
What to do?
So, you have completed a painting…do you varnish it and if so what level of gloss do you use? It’s really up to you; we have covered the benefits of varnishing, let us now discuss some caveats. The glossier the varnish the more it will saturate the colors beneath it but, the trade off is a limited viewing angle of the painting. Paintings with glossy varnishes have to be placed on a wall with proper lighting or else they may exhibit distracting glares from strong direct lighting. The best way to view a painting beneath a glossy varnish is directly in front of it with much indirect light. Spot lights aimed at the painting will yield the worst glares. Your painting must be completely dry in order for you to properly add a varnish; otherwise you risk the varnish actually becoming permanently part of the paint beneath it. If this happens, when the varnish is removed for cleaning in decades to come, some of the actual painting may be removed and not just the varnish. With some oil paintings you should wait months before you varnish, allowing plenty of time for the oil to dry.
I would like to conclude with a few last thoughts on choosing a varnish. In my experience, paintings with deeper tones, such as ones that use many dark browns benefit the most from using a varnish as it will bring out their warmth, especially if the painting has been created with layers of glaze. Think twice before using a glossy varnish on a painting with a heavy impasto. This heavy texture in the paint will be sure to show distracting, spotty, glares under any type of lighting. Always follow the number one rule of art conservators: what ever you do to preserve and protect a painting must be reversible. Only use varnishes intended for paintings and the varnish should be able to be removed with some kind of a solvent later on.