Beer-Bottle Brown (thanks Esa!) is a 50-50 glaze that has a high percentage of iron in it. With one coat, it looks real cool but sometimes produces these little bubbles in it. Usually just one or two, somewhere, never know where, I can re-glaze it and it will smooth out beautifully, but you loose some of the rich brown. So sometimes I will leave the little bubble in the glaze as long as it is not inside the pot, so the colors and richness are not lost.
Eh? . . . handmade, again.