Start over! A teacher I know had the students roll out terra cotta clay, and
tear it into large pieces. The students then used black underglaze or black
engobe to paint motifs...similar to greek pottery. Some students drapped
theirs over a curved form to dry so it looked more like a shard from a pot or
vase. The pieces look great, can be done in one class period and then
fired...no glaze firing necessary. You could look at many examples of greek
pottery and talk about legends and myths as themes on pottery.