Warning: VERY long post. Only read this if you’re interested in pate de verre, because this is the length of a small book…

Couple years ago a lovely artist named Cynthia (not me…Cynthia Oliver), organized a virtual artshow of warmglass artist self-portraits. It was a great deal of fun, and after seesawing back and forth on what to do, I did a minimalist line drawing in a reactive powder (above, left).

Cynthia’s now back for round two, and for my entry this time (above, right), I chose an old love I’ve recently returned to, pate de verre. I also experimented with a growing fascination: the trompe l’oeil and proportion effects that artists have historically employed to pack a lot more information into a work of art.

(For a look at the entire virtual exhibit, visit the Self-Expressions blog)

Quite a change, eh? I’ve generally avoided discussing heartwork stuff, i.e., sculpture and statement pieces, but lately they’re kinda seeping out, and I thought this was an interesting exercise with some knotty problems. The techniques are a combination of stuff I’ve learned from some classic PdV instructors, the wonderful Alicia Lomne, and my own experiments. So…

The actual pate de verre was relatively simple–this is an open-faced, hollow piece, mostly straightforward to invest. The work was all in the model…and in making color choices. I’ve been doing a lot of single-color sculpture lately, and was tired of it. On this one I wanted as saturated and Sunday comics-like as I could get.

I’ve gotten ribbed a few times for my habit of expressing disbelief by schoolmarmishly looking over the top of my glasses, so I decided to use that angle for the portrait. I took a few overhead photos of myself, set up a high mirror in the studio for reference, and set to work.

I started with a block of styrofoam, cut to 9x12x2.5 inches, covered it with a half-inch layer of my favorite clay (Hanjiki porcelain). Then I traced some light position lines onto the clay. I wanted something on about a 1.5X to 2X scale, and it soon occurred to me that to get the angle I needed to make this work, the forehead would need to be about 8 inches thick and–since the bottom would be recessed a couple of inches–the piece would probably hit 10 inches or so in depth. Since the piece is hollow, the thickness wouldn’t be an issue, but mounting and displaying probably would be.

selfportrait11.jpgInstead, I decided to play with proportions to see if I could get a similar effect in a flatter plane. The forehead would be closer to the viewer, therefore larger; the chin would be more distant, therefore smaller. I played around with the model quite a bit, seeking an angle/proportion that pleased me.

My rough draft (right) looked more like a Calvinist martyr than a dubious Cynthia. This one was too flat, too scary, and the nose was the one I wanted, not the one I had. I piled on more clay and started making it me. (Round 2, below right)

All the time I was adjusting the proportions and angle of attack (and noticing that my nose was out of joint and I looked scary-nasty, above).

selfportrait22.jpgI also needed to add the glasses, first in clay until I realized that (1) getting a thin layer of clay OUT of the mold would be bloody near impossible at that angle and (2) getting the glass INTO the mold and having it actually look like glass would be equally tough.

At the same time, the clay’s me-ness was increasing, which was nice.

I eventually removed the clay spectacles, cast them in glass, and attached them to the model. In this image (below, left), you can see the proportions and foreshortening of the model.


I also tried enclosing the face in a sloping “fence,” to see if it increased the relief effect (didn’t seem to, so I took it off). Finally, I invested the model. I lacquered the clay and coated it with release, smoothed on a face coat of plaster/silica, then backed it with Uroboros mix, an oatmeal-like, fiberglass-enriched strength coat.

I had the bag on hand, but if I hadn’t I would have added chopped fiberglass to the same plaster/silica, maybe added an interim layer of investment-coated fiberglass strips, to ensure the mold didn’t crack and spill glass. (Although  it’s probably not a huge issue with this particular piece.)


The image above shows the styrofoam core (which gives me a solid base and keeps me from using up clay at an even more prodigious rate) being removed and the clay skin that actually forms the model.

It also shows the feet I’ve added, that both keep the mold level in the kiln and get it off the kilnshelf so hot air can circulate all around the mold.


Anyway, I finished taking the clay out, cleaned up the mold and corrected a few areas (especially notice the spectacle “inclusions” left inside the mold below the eyes, in the above right image).

Then I wrapped the outside of the mold in wet paper towels and plastic wrap to keep the mold moist, and started packing. First, I laid down a color layer  by sifting some fairly strong tones of BE powder onto the wet mold surface.

That way I’d get the highly saturated “Dick Tracy comics” hues I was after, and then let the structural part of the glass add the depth and luminosity.


Then  I began laying in frit tints, powders mixed with fine clear frit. With each successive layer (there were four in this piece), I used less and less powder, until I was only laying in fine clear frit. I’ve found that this improves the translucency and makes the work seem to glow from the inside.

When you’re doing pate de verre you have a lot of choices in glass placement and packing. I had one bad experience with binders early on and tend to prefer drypack where possible.

In this piece, I had perfectly vertical sides, so I chose to use a binder right up until the final, clear layer. Normally, I’d be VERY precise with binder proportions, weigh everything and mix exactly, to ensure I had the same packed texture throughout. In Alicia Lomne’s class I was charmed by the great success she’s had with a few schpritzes of water and dollops of gum arabic, so I opted for that here as well. Worked well.

Originally, I’d intended this piece to be hollow, a five-sided box, and therefore needed to keep the vertical sides from collapsing in. So I fired with a talc core, i.e., I dumped plain old talc from the ceramics supply store into the packed piece until it was level with the top of the glass.

selfportrait6.jpgThat turned out to be the big problem: I forgot to factor in the insulating value of the talc in the mold and fired as if it were a thinnish open-faced mold.

As a result, I underfired it, and the piece came out of the mold looking like sandstone, not alabaster (below). There wasn’t enough purchase for the spectacle inclusions, which therefore stayed in the mold. (drat) ONLY time I’ve ever had this problem, and I was absolutely disgusted with myself.

Normally, I’d toss the piece, recast from the model, and redo. In this case, though, I didn’t have a spare model and everything else was well-nigh perfect. So I decided to reinvest the glass and refire. As I’ve explained in other posts, though, the glass needed to be smoothed for this to work.

Casting expert Hugh McKay suggested I try a 50-50 mix of lard and beeswax, applied like auto bondo. Worked like a charm, and the surface after the second firing was absolutely smooth and gorgeous. (happy sigh)

I used the second firing to correct a couple of things: eyes were too light and needed some iris detail, so I mixed that in with the beeswax/lard. Also, it had occurred to me that a deep hollow box might be a tad too fragile to hang well, so I let the sides collapse. Still had trouble with the spectacles, mostly because I was ham-handed with removing the investment. I finally made more and glued them on.

About the only other nit with the finished work was that I’d somehow erased the dubious look I’d had in the model by a tiny bit. I think Me looks a little more bewildered than disbelieving. OTOH, bewildered may be my native state, so maybe the glass was trying to tell me something.  😉

This was a fun exercise. I’m not sure I’d want to do a lot more–but I enjoyed this one.