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Aesthetics of Varnishing Transparent Watercolor: Creating the Least Change

12 thoughts on “Aesthetics of Varnishing Transparent Watercolor: Creating the Least Change”

    • 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

  1. 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

  2. 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,

  3. 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


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