below is an image of the bacteria plates i was working on for a doctor i work with. i had scavenged some underglazes that were getting trashed at the studio to use for the color. i covered them with underglaze while leather hard and sgraffito’ed the image. i once fired them, putting clear glaze on top of the underglaze while everything was still bone dry. unfortunately when they came out of the kiln chunks of underglaze were flaking off. i thought it might be because i had once fired them?? so i remade them, but this time bisqued the underglaze on, THEN clear glazed and glaze fired. same problem. any idea what the problem could be? i’m stumped. i decided to get rid of these underglazes and go with something new. news to follow.