Tuesday, September 3, 2019

Always More to Learn

Amaco Velvet underglaze on Waxy White Glaze (recipe below), on Laguna's 900 claybody
Students are like those fabled bumblebees that didn't know they couldn't fly; sometimes they don't know they can't do a thing, so they go ahead & do it, and we all learn something! That happened in one of my classes last week.

If she had asked me, I would have told Jesse not to do it; putting underglaze on top of glaze, I would have predicted, would have crusty, unpleasant results. And I would have been so wrong! She did it, and - surprise! - the underglaze maintained its brilliant, right-out-of-the-jar colors, but took the waxy sheen of the glaze. Not all of them - blue turned watercolor-y and periwinkle, the black & brown were...not great - but the hot colors were amazing. Red & orange & yellow like I've never seen in reduction.
So I tried it, with the few underglazes I had lying around, and had the same results! All of the underglazes used were Amaco's Velvet series; I applied mine in 3 coats. (Jesse didn't know exactly but she said "thick." I used Flame Orange, Radiant Red, and Royal Blue. As you can see, the Royal Blue turned more of a watercolor-y periwinkle; the others are right-out-of-the-jar hues.
Amaco's velvet underglaze on Waxy White Glaze
on Laugna's 570 porcelain

We only tried one glaze (so far!), and that is this one:

Waxy White (not sure the origin, but I got it at Portland Pottery)
^10 reduction

4100 Custer Spar
1200 Gerstley Borate
700 Dolomite
1500 Talc
500 EPK
2000 Silica

3 comments:

Susan O'Hanlon said...

Interesting results! There's always something to learn or experiment with, right? FYI, I screen print with black underglaze on Val Cushing's matte glaze and it gets a halo type effect (when it works) that is lovely. I've found the trick to be letting the glaze coat dry for a day or two before screening onto it.

Barbara Rogers said...

Thanks. Someone did the same thing in our studio the other day. "What would happen if..." but nobody knew. Our studio is all cone 6 though. So we shall have to do some tests too! Thanks for sharing!

Unknown said...

I also use underglazes along with my translucent glazes to get that watercolor look. It doesn't seem to matter in small amount but I never used thick layers. Interesting results!