Underglazing for Art a Day Project

a coat of wet terra-cotta under-glaze on the screaming face, before wiping

I finished the building for my Art a Day projects early last week and have been glazing since then. Right now I have 50 pieces in the cooling kiln and the rest are being glazed today. 

abstract and politics bulbs used different clays

I made the two sets of 30 from two different kinds of clay. The abstract bulbs are made with a reclaimed stoneware from last summer and the others are made with a red mica clay that I thought was similar to the clay I used for last year's political bulbs.

the new mica clay and the old political bulb clay

As it turns out, the new clay is much lighter in color and more sparkly than the clay I had last year. They look the same in the bag, but last year's clay was a gift and I didn't replace it with the same type. My intent was to keep the tone of these political bulbs much darker than the bright layered colors of the abstract bulbs. Last year I did this, but I also had some issues with last year's clay looking splotchy. It may have been because I wasn't as careful as I should have been about getting light clay on the dark clay because I was working the same space or with the same tools. 

the new red mica clay with under-glaze inlay at cone 04

I also wanted to use a clay that is pretty itself because, unlike most of my work, I didn't plan to cover it all with underglaze color. The mica in this particular clay causes little sparkles to be seen on the fired clay surface. I wanted to use the colored underglazes and shiny glaze solely to highlight the textures, lines, and impressed letters of the finished pieces and let the dark, sparkly clay also be visible.

the new red mica clay at cone 08 (left) and cone 04 (right)

I initially bisque fired all the pieces to about cone 08. I was impatient and wanted to go to bed with the kiln off, so I shut off the kiln a bit earlier than scheduled. I was disappointed in the very light orange color of the mica clay at this low temperature. In the second firing I had a mixture of greenware to be bisque fired, some underglazed abstract pieces and a couple of glaze tests, so I fired to cone 04. The mica clay looks much nicer at this temperature.

bulbs and sprigs waiting to come out of the bisque kiln

I was given a bottle of clear glaze in a brand I don't normally use, so I wanted to test it on the new mica clay before applying it to the finished pieces. Immediately after bisque firing (at either temperature), the political pieces are clearly distinct from the abstract pieces. I tried to apply color and glaze differently, too. However, during building, some of the content started to bleed across the edges of the two groups as I worked. I ended up with faces, eyes, and hands done in both white and red clays and some of the pieces I made with white clay could probably fit in with the political group.

each bulb needs three coats of underglaze, so some are drying while others away their first coat  

All of the abstract bulbs required two layers of underglaze. I used mostly highly textured surfaces and I enjoy layering the underglazes one over the other. In most cases, I applied one color to the background texture, a contrasting color to the sprigged additions, and sometimes another color to highlight a dot or contrasting part of the sprig. 

two sets of bulbs with one or two underglaze layers waiting to be glazed

After this first layer(s) of underglaze, I fired all of the abstract pieces again. After the work came out of this second firing, I applied a second coat to most of the abstract pieces, then wiped it away incompletely. The fired first coat stays put when I wipe away the second color from the raised surfaces. This approach highlights the textures, because one color is visible in the deeper recesses of the texture or sprig and another color is visible everywhere else. Most of the abstract bulbs have 2-4 different colors of under-glaze, some have 5 or 6.

political bulbs and one "abstract" face with under-glaze waiting to be wiped

Because of when I finished building, I had some newly dry work to bisque fire as well as some abstract bulbs with one layer of under-glaze. I also fired some of the political bulbs with a wiped coat of under-glaze inlaid into the textures to see the mica clay color at that slightly higher temperature at to determine whether I needed glaze in addition to underglaze in the impressed texture areas.

a political bulb on top of some abstract bulbs, all have had the underglaze layer applied and wiped and are waiting for glaze

After I applied underglaze, re-fired, reapplied underglaze, and wiped the surfaces, in most cases I also applied a clear glaze to the surface. In the political pieces I will probably use a combination of fired underglaze with glaze and without. The underglazes I use are mostly Amaco Velvets which have a nice of a texture on their own, and at least one of my colors fluxes by itself at cone 04. 

under-glazed and wiped politics bulbs waiting for glaze

In a few cases, I added under-glaze color and/or clear glaze over whole sections of the political pieces to try to accentuate the subject and make it more recognizable. In one case I felt the MAGA hat just needed to be red, in the other case I felt the ice (ICE) needed to be glossy in contrast the the bulb out of which it projects. I used a satin clear glaze one the ice and the underglaze alone on the hat. The kiln is over 1000 degrees Fahrenheit now, so I won't be able to see my results until tonight or tomorrow.

clear satin glaze covers the ice cubes in "Melt ICE"