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How to Break Through the Glass Barrier in Your Watercolor Paintings

Ditch the glass barrier when framing your work and try sealing your watercolors with varnish instead.

This is a guest post by Matthew Bird, an award-winning watercolorist and sought-after instructor. Members can learn more from Matthew Bird in Illuminate, a live online event debuting January 18.

Matthew Bird watercolor varnishing
Tidal Harvest (watercolor on paper sealed with varnish)

My favorite time in the studio is that moment right before I sign a painting. When it’s successful, there’s nothing like stepping back and seeing the finished watercolor on the easel. I wish everyone could view my work this way before it’s placed behind a glass barrier that separates the viewer and reflects the room’s surroundings like a mirror.

This is just one of the reasons I began searching for a more novel approach to display my watercolors—a way to varnish or coat them, breaking the glass barrier that limits the full enjoyment of a work in watercolor.

Matthew Bird at work on Lemons and Silver (watercolor on paper, 29 x 21)

As the trend in varnishing watercolor works continues to grow, I think it’s important to share some of the best practices that have been developed. There are, of course, many ways to varnish a painting; what follows is the approach I’ve developed after consulting with numerous manufacturers, chemists and conservators.

The Substrate: What Will You Paint On?

Varnishing requires a rigid surface, and there are many panel options such as birch, hard board or MDF (medium density fiber board). My preference is a Raymar ACM (aluminum composite material) panel, which, if properly sealed, is a durable, lightweight and archival surface that won’t warp or corrode with humidity or temperature change.

Using a prepared panel saves time and effort, but what if you already have a finished painting, or you want to make your own panel with your paper of choice? In this case I recommend using Golden soft gel medium as an archival adhesive—brushed on the substrate as well as the on top of the paper. Weight it down with a bunch of art books and it will dry nice and flat.

Matthew Bird Watercolor Varnish
Magnolia Still Life (watercolor on paper sealed with varnish)

Ready for Varnishing

Once your watercolor is finished, you’re ready to seal and varnish your painting. If you’re a watercolor purist, it’s important to understand that applying a varnish, which adds an acrylic coating, will permanently change the nature of the painting.

There can be aesthetic changes to color, value and texture. Because of this, I strongly recommend experimenting on pieces you don’t care about too much in order to learn what type of finish suits your style.

There are three steps to varnishing a watercolor: sealing the surface; applying an isolation coat; and applying the top coat or finish. The first step is required, but the second two steps are optional. We’ll cover all three steps below.

Rethinking Watercolor with Matthew Bird: Live Discussion and Demo
Matthew Bird gave a brief demonstration of his varnishing technique on January 18. See how to join future sessions.

Sealing the surface with an archival aerosol spray will permanently lock down the water-soluble paint. There’s no way to brush on a varnish without disturbing the paint layer. (Brushing on a mineral spirit varnish won’t activate the pigment, but it will cause it to sink into the paper, which you don’t want.)

Once the painting is sealed, you have the option to apply an isolation coat. Then, any subsequent varnish layers can be stripped down to the isolation coat, and a fresh or different varnish applied later. The reason for taking this step is that you don’t always know where your paintings might end up once purchased, or how they’ll be cared for. Over time, dirt, smoke, pollen and even insects can take their toll. Or, perhaps you might decide you’d just like to try a different finish than the one you originally applied.

3 Steps to Varnishing a Watercolor

Step 1: Seal the Painting With Gloss Varnish

Spray at least six coats of gloss varnish onto your finished painting. Gloss best preserves color clarity and is recommended for all early layers. Satin or matte products can reduce clarity and may result in a cloudy or dusty appearance. Proper ventilation is important. If you don’t have a spray booth, you can do this outside, but always wear a respirator mask regardless.

Matthew Bird, Varnishing a Watercolor: Step One

Spray the varnish with your painting positioned upright or at a slight angle (not laying flat). Don’t spray from too far back, as particles can dry in the air before reaching the surface. Allow time for each coat to dry, and rotate the painting 90 degrees between each application to ensure even coverage. This is especially important if you use rough- or cold-pressed paper. Humidity and temperature can affect results, so be sure to read manufacturer’s guidelines.

Once your painting is sealed with gloss varnish, you’ll be able to move on to the next step without disturbing or reactivating the paint layer. Those who apply varnish with a heavier hand will need fewer coats. Applying too much at once will cause drips or runs, so practice your technique first.

At this point you could stop, or you could apply an additional coat, using archival matte, satin or semi-gloss for a different finish, and frame your painting as desired. Proceed to the following steps only if you want to be able to remove a subsequent varnish layer.

Step 2: Apply an Isolation Coat

Matthew Bird, Varnishing a Watercolor: Step Two

According to Golden Artists Colors, the definition of an isolation coat is a clear, non-removable coating that serves to physically separate the paint surface from the removable varnish. This is your backstop, a clear acrylic film that acts as a permanent barrier. Anything applied after this can be removed.

An isolation coat can be applied with a brush or sprayed with an airbrush or spray gun. This coat will dry clear, although depending on the thickness of the application, it may appear milky at first. Let the isolation coat cure for at least one day before moving on to the next step of applying polymer varnishing.

Step 3: Varnish the Top Coat(s)

In this final step, you have lots of options, not only in choosing the aesthetic finish (gloss, matte, satin) but also in the application via brush or spray, and mineral spirit acrylic (MSA) or water soluble polymer.

Matthew Bird, Varnishing a Watercolor: Step Three

I like to use Golden polymer varnish with UVLS, which is a water-based acrylic polymer varnish. UVLS stands for UltraViolet Light filters and stabilizers. It provides protection from ultraviolet radiation. The formula for dilution is 4 parts varnish to 1 part water for brush aplication, and 2 to 1 for spray application. This varnish is available in several finishes and is removable for conservation purposes. A second coat may be necessary to achieve your desired finish.

The choice of application is a personal one. The best way to achieve an even coating of varnish is to spray it on, but that’s not always practical. I prefer to use a da Vinci soft synthetic hair mottler brush (flat wash, short handle, No. 50) and apply it with the painting laying flat so there aren’t any runs or drips. A little goes a long way, so don’t submerge the brush too deeply. Keeping the varnish from away from the metal ferrule will also extend the life of your brush and make it easier to clean.

Hassle-Free Framing

Next comes the easy part—no longer is framing your work a tedious chore of cutting and assembling mat boards, backing sheets, Plexiglas and dust covers. Instead, just pop the panel into a frame and hang it up!

Matthew Bird, Punch Buggy Red
Punch Buggy Red (watercolor on paper sealed with varnish)

Where to Show Your Work

More and more watercolor societies are beginning to allow varnished watercolors into their shows and exhibitions. Any group that allows mixed media will likely accept them as well, but be sure to read the framing requirements in the prospectus as, in some cases, Plexiglas may still be required. For those interested in exhibiting in society shows, I keep a growing list of organizations that accept coated paintings.

Varnishing watercolor remains a new frontier for the medium and, while it’s not for everyone, the door is open wide for those who wish to explore the idea.

Matthew Bird, watercolor varnishing
Farewell to the Beach (watercolor on paper sealed with varnish)

Meet the Artist

Want to hear more from Matthew Bird? Check out the recording of his discussion with Scott Maier in Illuminate. Matthew tackled common misconceptions about watercolor and showed a brief demo of his varnishing technique.

Matthew Bird graduated with honors from Pratt Institute of Art, in New York City. He’s a Signature Member of numerous watercolor societies, and his award-winning paintings have been exhibited in shows around the world. A sought-after instructor, the artist offers online workshops from his studio and instruction on watercolor varnishing and other techniques he’s refined over the years. He lives with his wife and children outside of Baltimore.

Rethinking Watercolor with Matthew Bird

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