Thursday, June 30, 2011

Varnish pastel experiment

charcoal sketch on prepared panel
 Pastels have to be framed under glass to protect them. Glass is heavy. Glass can break during shipping and needs extra care. Plexiglass is an alternative but can generate static electricity. Static electricity can pull loose pastel dust and create a cloud on the inside of a framed piece. Plexiglass can also be less rigid than glass, and when used on large paintings (like my 4 foot square painting earlier this Spring) it can even dip onto the painting surface. What a pain!

So, that's the problem. I love pastel. I hate glass. Can I successfully varnish a pastel painting without having it change the beauty of the pastel?

original pastel painting, no varnish
 I created this small painting of birch trees. Gatorboard support with acrylic gesso, acrylic underpainting, acrylic pumice gel, and pastel on top.

Golden Archival Varnish, Mineral Spirit Acrylic Aerosol
 I thought I might be able to create an acrylic sandwich by using Golden's Archival Varnish Mineral Spirits Acrylic Aerosol.

Spray in a well-ventilated place, in my case outdoors under the overgrown Christmas tree. I sprayed the piece and let it dry for at least 20 minutes between coats. Five layers of varnish. 

What I found: 
1. When the first spray of varnish hit the pastel, all of the little pastel particles that were loose, suddenly became solid and obvious. Next time I will give the piece a sharp smack on the back to get rid of the loose stuff before I spray varnish on it.

2. The color darkened, but not as much as I expected. 

3. The pastel lost something when varnished. With the first layer of varnish, I lost my ability to change the painting, to add or remove pastel. And, the pastel became more plastic and less elegant. 

Overall, I was pleased with the results and I will try this again on a larger panel painting. Once the aerosol varnish sets up a protective surface on the painting, I can use a brush to add more layers of varnish, and to give the piece a different look. 
spray in a well-ventilated area
final result, varnished pastel painting on prepared panel

5 comments:

Suzanne said...

What an impressive end result. Lovely colors! You've given me a new idea for the pastel boards I have that are all different sizes than the usual cut glass for framing.

Cindy Michaud said...

I tried this a while back and hated the results...yours still has a bit of the "pastel" look...mine might has well been oil or acrylic. Hope you discover a fail-safe method! good luck.

Katherine van Schoonhoven said...

Hi Suzanne -- you should come and see the painting in person before committing yourself. It DOES avoid the glass problem, though, so it's a mixed bag.

Katherine van Schoonhoven said...

Cindy: I'm not completely sold on this method, especially since it changes the complexity of pastel. I agree, it has a plastic feel to me that reminds me of acrylic. Thanks for the good luck wishes. I think I need them!

Dewberry Fine Art said...

Wow Katherine. I wish there was a good fix to this problem.. I hate shipping pastels for this reason. I did ship one recently with just a glassine cover along with full instructions on what to do...get it to the framer ASAP. I only sent it that way because I knew the buyer. Pastels have such beauty. They need special care. So many people think pastels are all oil based. People are always amazed that they are soft and movable. They are delicate, but under glass they last centuries.