Special Effects: Steel Blue Opalescent
"When I put it in the kiln it was blue. When I took it out it was the color of mild steel. When I fired it again it was blue. What’s going on?"
Good question. Steel Blue Opalescent is a glass with some unusual working characteristics. When this glass was first being designed, we put it through a multitude of tests including firing it to full fuse temperatures. In all of these tests, it emerged from the kiln looking like it did in its cold form. Then after it was released and people began working with it, we started receiving calls from people saying the glass had turned a metallic color in the kiln.
We figured out that Steel Blue Opalescent does turn a shiny silver-gray at temperatures 1250-1400° F. At about 1500° F, the effect disappears and it returns to its normal color. We considered taking this glass off the market, but were convinced otherwise by kilnformers who had already conceived of interesting ways to augment their work with the special effect.