Photos: JoJo Bazilian/BazFoto Int'l
As I b'lieve I mention in the text, the glaze I put on my very first pots was Larry Bruning's "Opal Blue". I love it. It is, however, Larry's, which means I don't get to mix up batches of it on my own; and it runs, which means that when I put it on pots I have to put them on pedestals. Larry agreed to let me see the formula so I could re-engineer it. I agreed not to make the stuff without his explicit permission, and not to divulge his formula.
(He laughed when he saw one of my recipes a year or so later, because it didn't look even remotely close to his. I think I had maybe two or three ingredients in common with him at most, and the quantities I used were grossly different.)
Here's what Larry's glaze looks like, on one of my earliest bowls (I think it's from August, 1996):
You can see from the lower image that the stuff has a tendency to run & drip. It also leaves a tallish area around the rim that doen't get any real color. I've been working on that, because I don't like either of those characters.
(29 May, 2001)
As you can see, however, there is a wonderful blue-white
glowiness about this glaze, something you don't see in
my versions. I'm working on that.
I still haven't got a rutile blue that won't run, so I have a tendency to spray the stuff onto the pots. The results are very happy. (See below.) What I do have, nearly three years after I first saw Opal Blue, is a family of "Fake Opal Blue" glazes that have suitable coefficients of expansion for most of the clay bodies I use, and provide a range of colors from "pale and creamy" into blues and purples. I should confess that I suspect I've accidentally jacked up the contrast on the blue/purple stuff a bit, in the process of color-correcting the scan, but the colors do seem to be reasonably well rendered.
(29 May, 2001)
I should perhaps correct that: those glazes were perhaps not quite exactly matched for expansion, and while they provided good colors (some of them, at least), they did have one peculiar tendency: on some clay bodies, some of the glazes would make tiny golden flittery-looking things, deep inside the glaze. At first, I thought these were crystals of some sort, but when I looked at them under a low-power microscope I discovered that they were cracks in the glaze, more or less parallel with the surface of the clay beneath it. Pretty as they are, they indicate a loss of integrity within the glaze, so I'm working on eliminating them ...if I can.
(The inside of the vase I fingerpainted, by the way, is covered with the same glaze as the darker blue bowl on this page, poured rather than sprayed. That was the first test of this particular version of the glaze (dumb, I know, but I was fairly well convinced, on the basis of previous versions, that it would work at least tolerably well). I was happy enough with that piece to spray the rest of my test batch onto the bowl you see below, which is in the collection of Magdalena V. Bergin.)
Here's an example of the creamier end of the range, from the Joss Institute collection:
(29 May, 2001)
I've been working on these glazes again, recently. I am currently trying to get them to show the blue-white glow that is characteristic of Larry's original, while retaining good colors otherwise, and with an even better match to the thermal expansions of the clays I'm now using. This proves to be an interesting exercise (ahem), and I'm only partway there. Here is a photo, showing a combination of three versions of the previous family (left), a distinctly drab attempt in the middle that nonetheless suggests a potentially interesting direction, and my first shot at blue-white (right), with insufficient rutile in it. True, it has only the slightest hint of the desired glow, but it is certainly moving in a good direction. There is even a tiny spot of rutile blue on it, at the right edge of the tile just below the pale band at the top. When I get a bit more rutile into the glaze, it will become a lot bluer.
