For artists who push the boundaries of traditional watercolor, work in sizes large enough that framing is not practical, or just dislike the barrier created by glass, varnish is a valuable option for protecting their paintings.1
Varnishing is likely to alter color, value, contrast, granulation, and the appearance of the paper in a watercolor painting. These modifications can be acceptable when balanced against the freedom varnishing offers.
In a previous article2 we investigated the changes that occurred when varnish was applied to washes of QoR Payne’s Gray, a paint chosen for its status as a chromatic neutral. The current test expanded our investigation to encompass washes of QoR Ultramarine Blue (PB29), Benzimidazolone Yellow (PY154), and Quinacridone Magenta (PR122) coated with GOLDEN MSA, Polymer, and Archival Varnishes. This combination allowed us to build a broader understanding of the aesthetic changes created when a watercolor is varnished. This article will discuss the varnish application that created the least aesthetic change to the watercolor over which it was applied, paying particular attention to the watercolor it changed the most.
The “Least Aesthetic Change” Challenge
We wished to see which varnish application came closest to the appearance of transparent watercolor on paper. Archival MSA Varnish Matte applied over Archival Varnish Gloss without an isolation coat won the “Least Aesthetic Change” accolade. We selected Ultramarine Blue as a visual example of this test (Image 1) since it presented the most change even when coated by the winning varnish. More information on the structure of our test may be found further into this article.
Depending upon the viewpoint and lighting, Matte Archival Varnish applied without an isolation coat marginally darkened and desaturated color. The matte sheen also slightly subdued the appearance of paper texture. Lighting and point of view influenced how easy it was to see these changes.
There also appeared to be variation in how people perceived the changes. Those of us with more background in watercolor found the differences to be obvious, while others thought the alterations so slight as to be negligible. Due to this difference in interpretation, plus the impact different colors, wash dilutions, and papers might have on the results, we would recommend that artists conduct their own tests before varnishing a watercolor painting.
Related Matte Varnish Results:
The runner-up to the combination causing the “Least Aesthetic Change” was structurally different through the use of an isolation coat between the two types of Archival Varnish. The isolation coat created a shinier surface than the Archival Varnish Gloss layers did by themselves. As a result, when Archival Varnish Matte was applied on top of this coating, it appeared less matte as well. Color also darkened a bit more than seen with the winning Archival Varnish Matte without an isolation coat. The varnished areas warmed color slightly, resulting in a more noticeable but still slight desaturation of color.
The other matte varnishes created more changes to the QoR Ultramarine Blue washes and watercolor paper (Image 2). Brush applied MSA Varnish Matte and Polymer Varnish Matte both desaturated color, and either lightened or darkened the paint or paper surface depending upon viewer position and lighting. The lightening is more obvious on darker color applications, and was seen with both of these brushed-on matte varnishes. Polymer Varnish appeared to darken the blue color slightly more than MSA Matte, while the MSA warmed the color more than Polymer Varnish Matte. The light blue wash shows these changes most clearly. Interestingly, these two matte varnishes appeared to emphasize granulation in the dark and medium washes of Ultramarine Blue, which is unique among all the varnishes tested.
Why would someone use an isolation coat?
An isolation coat creates a barrier between two layers of product. Since GOLDEN Varnishes are removable, having an isolation coat would allow a conservator working in the future to remove and replace the final layers of varnish without damaging the painting. Potentially, this replacement could return the artwork to its pristine just-varnished state, and rejuvenate a surface marred or dirtied by time. However, the more layers of product on top of a painting, the greater the aesthetic change will be. An artist should balance the potential for varnish replacement against the alterations an isolation coat might bring.
An isolation coat is especially important for brush application of MSA over an absorbent surface such as paper. Without a barrier, the solvent-based MSA sinks directly through the Archival MSA Varnish and into the paper. As our test shows, however, every additional layer over the painting’s surface increased the possibility of aesthetic change. Comparing the test results for Archival Varnishwith and without an isolation coat shows this clearly.
Result Summary:
Varnishing created changes to color, value, paper texture, and sheen. In some cases, varnish modified color intensity and appeared to slightly warm the color of paint and paper. The appearance of change can be subjective, with varnished color appearing darker or lighter depending upon viewpoint and lighting. Viewing context also altered the perception of sheen and texture. We found that Archival Varnish Matte applied without an isolation coat created the least changes.
The Structure of the Tests:
We began with 300 lb. / 600 g.s.m. Fabriano Artistico Cold Pressed Extra White Watercolor Paper. Over this, we brushed horizontal dark, medium, and light washes of QoR Modern Watercolor Quinacridone Magenta, Benzimidazolone Yellow, and Ultramarine Blue. The test also included an area of unpainted paper. This created four horizontal bands across the paper (Diagram 1).
We applied varnish in vertical strips perpendicular to the horizontal washes. Uncoated “control” areas of paint and paper remained between each varnish test to allow for more accurate assessment of change. This created alternating vertical sections that were either varnished or left untouched to act as ‘controls’ for comparison. The process of creating the test specimens is described below:
First, to protect the water-sensitive and absorbent surface of paint and paper, four coats of aerosol Archival MSA Varnish Gloss were sprayed only where the varnish would be applied. Three or four coats are usually needed in this step, for the goal is to seal the surface and lock down the paint so no color will lift if a waterborne acrylic is brushed on the surface. Gloss preserves the greatest color clarity in the final result and is our recommendation for all early layers when varnishing.
Second, once the varnish was dry, an isolation coat of Soft Gel Gloss diluted 2 parts Gel to 1 part water was brush applied to three of the four varnish test areas. The goal with the isolation coat was to create an even, glossy surface and further seal the painting in case the final varnish needed to be removed in the future. An isolation coat was used to prepare for the MSA Varnish, Polymer Varnish, and one of the two Archival Varnish tests. The fourth varnish test area was preserved without an isolation coat.
Third, we applied the final varnish application. The MSA was diluted 3:1 varnish to MSA Solvent and the Polymer Varnish was diluted 4:1 varnish to distilled water. These two varnishes were brushed over dry isolation coats. The third test area with an isolation coat was sprayed with three layers of Archival MSA Varnish. The fourth test area, without an isolation coat, was also sprayed with three layers of Archival MSA Varnish. The two Archival Varnish applications would allow for a comparison between the Archival Varnish with and without the isolation coat.
Lighting for the Photographs
Two different lighting situations were used when photographing examples for this article. Light directed on the surface from the side created a more diffused illumination that allowed us to photograph color changes with less interference from varnish surface reflections. Moving the side light sources more to the front increased glare and emphasized sheen and its impact on the cold pressed paper texture.
Conclusion
Varnishing transparent watercolor permanently changes the painting while adding a protective surface that allows the artwork to be displayed without glass, much like an oil or acrylic painting might be.3 In this article, we discussed Archival Varnish Matte without an isolation coat since it came the closest to the original look of the watercolor on paper. We discussed the Matte Ultramarine Blue results because this color showed the most change even with the “winning” varnish. Please also keep in mind that the addition of acrylic varnish to a transparent watercolor might cause the artwork to be categorized as mixed media by some watercolor societies. To see images of all of the test panels, please go to the end of this article.
There is a component of subjectivity when applying varnish or evaluating the finished surface. Variances in application and materials may create different results, and viewpoint and lighting also change the way a varnished surface reads. We believe it would be best for an artist to create tests by varnishing sacrificial painted surfaces created with the paints, techniques, and papers used in the artist’s own watercolor paintings. These varnished examples would provide a more accurate example upon which to base a decision about whether to varnish a watercolor painting. The artist then would weigh the transformation against the liberating benefits offered by varnishing, to see if this is a direction he or she wishes to pursue when protecting a painting.
References
1 Cathy Jennings, GOLDEN Archival MSA Varnish Over Transparent Watercolor on Paper, Justpaint.org, October 4, 2017, Accessed October 3, 2017
2 Cathy Jennings, The Aesthetics of Varnishing Transparent Watercolor, Justpaint.org, May 15, 2017, Accessed October 3, 2017
3 Golden Artist Colors, Application Information Sheet: Varnishing Watercolors with GOLDEN Products, accessed October 4, 2017 and Golden Artist Colors, Resource Guide: Varnishing, accessed October 4, 2017
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Would love to try this!
Hello Irene,
Testing can be fun, and we encourage you to give varnishing a try! Please let us know if you have any questions by giving us a call at 607-847-6154 or emailing [email protected].
Happy painting,
Cathy
Is varnishing an acceptable alternative to mat and glass for transparent watercolor among most watercolor guilds and contests nationally?
Hello Karen,
Thank you for your question. Although interest in varnishing watercolors is increasing among artists, it is not yet accepted by the majority of individual watercolor organizations. We recommend checking with the rules of the societies and within the prospectuses for individual exhibitions. Sometimes these refer to varnishing as “sealing” the work. We understand that the National Watercolor Society recently began accepting varnished watercolors into its exhibitions. Hopefully other organizations will also become inclusive of varnished watercolors.
Best Regards,
Cathy Jennings
Dear Cathy,
a very interesting and informative article. I was wondering about the drying times between varnish coatings. Archival varnish-isolation coat- archival varnish, archival varnish-isolation coat-MSA/ polymer varnish. What about MSA(spray)-isolation coat-MSA ?
Kind regards Sam
Hello Sam,
Dry times are influenced by environment, absorbency of the paper, thickness of applications, and whether the paper has been adhered to a board. All of these aspects should be considered when testing and practicing varnishing watercolor paintings.
Generally, we recommend waiting about 20 minutes between layers of Archival Varnish. Since watercolor paper can be absorbent, it might be good to wait a little longer as the number of layers increase. Once the Archival layers are finished, I like to wait at least a week before brushing an Isolation Coat over the surface, especially if the watercolor is on a board. A shorter time (2-4 days) may work for unmounted paper since drying can slowly continue out the back of the paper. How much Archival Varnish is on the surface influences dry time, and the amount of varnish is determined by the number of layers and the heaviness of the spray application. If there is any mineral spirit scent to the Archival layers, definitely give the painting more drying time. We usually recommend 2-7 days of drying between a brushed-on Isolation Coat and the application of a varnish. If using Polymer Varnish, it might be fine to apply the varnish over an Isolation Coat after 2 days. With a mineral spirit varnish like MSA or Archival Varnish, it is important not to trap moisture under the varnish layer so giving an Isolation Coat longer to dry can be helpful. A page with links to our varnishing resources (including videos and tech sheets) can be found here.
We hope this is useful, and we are here when you have more questions.
Warm Regards, Cathy
Hello,
I have some doubts and my case is a different one. I’m doing fountain pen inks on cotton paper artworks, which is similar to watercolor but they have an even greater danger of fading colors over time and changes for water or humidity.
I would only like to use the method of 4 coats of archival spray gloss and 1 of archival matt, so as not to alter the color and texture too much and I really want to avoid the isolation coating with soft gel.
Do I have to put some archival coat on the back of the paper, to protect it from humidity? they are not mounted
Is it okay to just put 4 coats of Archival Glossy and 1 of Matte?, since fountain inks are more likely to fading, but I would prefer as little as possible
After the first Archival glossy coats, can I add the next one with the MSA varnishes? I haven’t understood that part yet, or MSA varnishes are only used after an isolation coat?
With these 5 coats of Spray Archival, is it enough for the artwork to not have glass?
About storing artworks already varnished, what paper or protection do you recommend between each one?
Thank you very much, I would love to have this information
Hello NL,
Thank you for your questions. We have not tested our varnishes over fountain pen inks. We understand there are now pigmented lightfast fountain pen inks, and we would advise their use if you are concerned about fading. Colors crafted from pigments often have better lightfastness than colors made from dyes. We have an article which compares different protective options for watercolor, which includes 4 versus 6 coats of Archival Varnish on both lightfast and fugitive watercolors. Please be aware that the person spraying has an impact on how much varnish each layer contains so results can vary. We do not advise brushing diluted MSA onto paper unless there is an isolation coat or other layer of water-borne acrylic applied first, as the MSA will sink into the paper. Acrylic Varnishes do not create moisture barriers as vapors can still pass through the layers. We would not recommend putting Archival Varnish on the back of your paper.
Our recommendation for artworks with an acrylic surface, including acrylic varnishes like Archival and MSA, is that nothing touch the surface of the artwork. This can make storage and shipping difficult. Silicone Release paper from an art conservation supply retailer could be used as interleaving, as it does not stick permanently to acrylics and so could be peeled off if it does stick. Sticking is likely to cause a sheen change, though.
Testing before varnishing an artwork is always a good idea, and would allow you to check if there is any interaction between the fountain pen inks being used and the Archival Varnish.
Best Regards,
Cathy
Hi Cathy, thank you so much for sharing this information! I’m a novice watercolor artist who sometimes participates in Plein air competitions with a very quick turnaround between finishing a painting and displaying it for sale. As I understand it Archival Varnish spray protects the painting from UV light but not so much from dust/water. On the other hand, I’ve seen artists use wax medium which looks good and I believe protects from dust/water but notably not from UV light. Is there any way to varnish in a short time period (24 hours or less) but still get the best of both worlds? Can both varnish methods be used together? What about a UV topcoat? Let me know if I’m misunderstanding anything.
Thank you!
Hello Beth,
Is there a reason not to consider simply bringing hinged matts the size of the intended paintings, and using those to display the artwork?
Varnishing in this situation both might be possible and is likely to be complicated. It would be important that the painting be completely dry before Archival Varnish is applied. Another consideration is what to do with the varnished paintings while traveling. Since acrylics are thermoplastic, it is possible for the varnish layer to stick to something pressed against it even when the varnish is completely cured. This is more likely in hot and humid environments, but can also occur when paintings are stacked. The flip side is that when it is cold the varnish might crack if the paper is flexed. Our best recommendation is for the paper to be adhered to a rigid surface before varnishing.
Silicone Release Paper, a material available through art conservation materials retailers, can be used as interleaving between varnished paintings, since if the varnish sticks it can be pulled off of the silicone surface. However anything sticking to the surface might change the sheen.
Putting wax over the Archival Varnish is not something we have tested. We would recommend making sure the Archival is completely dry (which is likely to take the whole process over the 24 hour limit), and that the wax both does not yellow and does not contain a solvent that might interact with the Archival Varnish.
UV Topcoat does provide UV protection (just like our varnishes do), however it is waterborne so likely to re-wet the watercolor if applied directly to the painting. The topcoat was also formulated to hold brush and palette knife tool marks, so would not create a smooth surface. Since it is an acrylic, the Topcoat also is thermoplastic and would have the same travel and storage issues as the varnished surface.
We hope this is helpful, and we wish you happy painting! Cathy