Play Date with Pastels?
September 19, 2009
I’ve been playing with pastels since high school. I love using them and was always on the lookout for a way to get the feel of pastels into fiber or glass. With fiber, you can saturate cloth with thinned acrylic paint, then draw into it with pastels and the pigment becomes embedded into the cloth. With glass, it was close to impossible until a few years ago to get this effect.
If you’ve taken my ‘Exploring Glass Powders’ class, you know I try to fit a lot into one day. There’s precious little time to really explore any of the avenues possible, other than trying everything we can and then playing further with each application after you’re back in your own studio.
I want to share my tests from one of my favorite products from two companies, Underglaze Crayons and Glassline Chalks. A shameless plug as I sell the Underglaze Crayons in my Artfire shop and Glassline has given their chalks to my students at the Glass Craft & Bead Expo!
Both products work like pastels on a toothy, or rough surface. The usual surface treatment for glass is sandblasting it to get a rough surface, but what if you don’t have a sandblaster? Powdered glass! Sift a thin layer of clear powder over the entire surface of your sheet glass substrate, then tack fuse. In my Paragon kiln I fire to 1325º and hold for 10 minutes to achieve a toothy surface. In my Skutt kiln I fire to 1300 and hold 10 minutes. When the glass is cool I can start drawing on the now roughened surface.
You can use clear, white, or any colored sheet glass as your canvas. To get the toothy surface without a blaster, you can use clear, white, or any color of powder fired on for texture. Once you have your ‘canvas’ readied it’s time to play with these fun chalks.
As you know before I begin a project I do a series of tests. I use the smallest size glass possible that will let me put as much information as possible on each test. For me, this is a two inch surface. I’ve pre-fired a dozen small clear ‘canvases’ with clear powder and am now ready to play. These photos show my tests of the colors as well as differences (none noted other than color choices) between Glassline Chalks and Underglaze Crayons. I also wanted to explore how they look clear-capped compared to fired on the top surface of glass.
I applied water with a paintbrush to see if I could get the same watercolor effects that you can with pastels. I also wanted to know if there’d be any chemical reactions between the pigments & glass like there is with certain colors of glass. Also, how does it look clear capped; clear capped with irid; or left alone & fired on top of the glass. I always test with clear, white, and black bases to learn how any given experiment will look against a light and dark background. The clear is to audition the surface treatment against any other color of sheet glass.
My results after firing:
No chemical reaction atop French Vanilla.
The sandblasted substrate has a smoother line than the tack fused powder substrate.
Colors are difficult to see on a black background.
If the pigment is on the surface of the glass, the excess will wipe off like mica does.
I like clear capping with iridescent glass, irid side down.
You can tack fuse (not shown).
I like the watercolor effects.
Both products fired the same for me in my kilns; each set of products has different colors; and not enough colors available in either product!
Have you played with these chalks? What do you think of them? If not, give them a try – another shameless plug, please buy Underglaze Crayons from me! Make a play date with yourself to try something new. I’d love to see your results!