Excavations of pre-pottery levels at Gua Talimbue and Gua Sambagowala in Southeast Sulawesi, Indonesia, have yielded nearly 4kg of baked-clay fragments, half of which exhibit intentional patterning. The fragments appear to derive from clay hearths. Here, the authors link the patterning on Early Holocene (c. 9900-8800 cal BP) fragments with the intention to enhance the appearance of the hearths' rims. During the Mid/Late Holocene (c. 4500-2000 cal BP), patterning shifts to the interior surfaces. The effort and specialised skills required to impress patterns on these hearths is, to date, unique in the archaeology of pre-Neolithic Island Southeast Asia.