Saturday, April 10, 2010


I'm trying this new thing--no, not test tiles, but taking pics of my test tiles after they're fired.

The tiles are carved so that I can get an idea of how a glaze is going to break over a carved piece. Some glazes highlight carved details, some glazes completely obliterate carved details.

The other thing test tiles tell me is how a glaze is going to look over the kind of clay I use. Most commercial test tiles are done on smooth white clay to highlight the color of the glaze. I don't use white clay, I use a relatively dark red clay which has an effect on the color of the glaze. The "violet under osiris" tile, for example, shows this tendency. You can see that the violet comes through all right, but the osiris only looks blue where it's thickly applied, as in the crevices of the piece. Over the flat parts, it doesn't really look blue at all.

Sometimes, of course, it does look blue, as it does in this test piece:

Same clay, same glaze. Here, you can see that it did go blue on the inside of this vase. That's because it's very thickly applied. If I tried that on a flat piece, or on the outside of a tall piece, the glaze would run and possibly stick to the kiln shelf.

See, this is why I love glazing. I love building relationships with glazes like this.

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