Fire is FUN part 2: Pigment

Pompeii wall fresco, photo by me, at the ISAW

Earlier this summer I got to see the Pompeii in Color exhibit. As we all know, Pompeii got buried in volcanic ash, which must have varied in temperature-because there was a painting that showed the effects of heat on only parts of what started out as a monochrome yellow painting! (See photo above.) Tens of thousands of years before Pompeii, humans discovered-and used-the trick of changing the color of earth pigments with fire. I’m a kind of artistic re-enactor, so I wanted to take the fabulous “garden gold” that was dug from the Earth on the NCC East 40 where I’m doing my artist residency this summer, and “burn” it.

From the very start of me painting, which is-ahem-a lot of years ago, I have been using burnt sienna and burnt umber, in addition to their unburnt versions, raw sienna and raw umber. Anyone who paints will be familiar with these basic earth colors, and yet, apparently there aren’t lots of weirdos like me who want to burn it themself. I got the idea of putting the dry, powdered garden gold pigment (essentially clay with the impurities taken out by Walter Heath and NCC ceramics students) into a in tin “kiln” just like I did with the vine, see yesterday’s (7-1-22) post. I actually did the “burn” in the same fire as the charcoal and vine pigment, but decided one long post on both would be too long and complicated. Below is my porcelain palette with the garden gold pigment before firing (left) and after (right.)

I had a fairly tall tin, and only filled it about 1/10 full. I have zero idea if that made any difference. Well, maybe I can hazard an educated guess. I do know that metal conducts heat, so maybe if the tin were full, the pigment in the center would not have reached as high a temperature? Honestly, I don’t know. I also had no idea how long I was supposed to fire the pigment to get the red color. I just did it an hour like the charcoal. TA DA-IT WORKED! I’m super happy with the color of the burnt pigment, and want to do another burn because I didn’t do enough. That second burn could vary, lighter or darker. Much like my approach to natural dyeing, I get delighted by all the variations I can achieve, I love making colors. I’m not a factory. I suppose you could say it’s a kind of boutique approach to making color, and I have no desire to become a factory. My idea for next time would be to put some rocks in with the pigment. Rocks, I know, also conduct heat, so if I pack the tin so the rocks are as close to the center as possible, all the pigment should get heated up. That’s my theory anyway. 

Egg tempera is my go-to making paint to do tests. You don't have to make a whole tube, I used the pigment in the photo above, added some egg yolk, mixed with a martini stirrer right in the palette and presto, it was ready to make the paint swatches below.

I have to admit, I haven't cracked any of the rocks I burned in the fire on Wednesday. The color of a solid rock is not always the color of the pigment it makes, so I have one more surprise waiting for me when I get a chance to grind those rocks and see what colors they make.