The kiln-firing process is critical in porcelain sculpture production, yet it often introduces defects that compromise quality. Among the most frequent issues are cracks, which occur due to rapid temperature changes or uneven clay drying. Hairline fractures or deep splits can render sculptures unusable.

Glaze imperfections are another common problem, including pinholes, crawling (where glaze pulls away from the surface), and blistering caused by trapped gases. Color inconsistencies may also arise from improper glaze mixing or firing temperatures.

Warping and distortion plague thin-walled pieces, as uneven heating causes sections to shrink disproportionately. Kiln shelves with uneven surfaces exacerbate this issue. Additionally, bloating—bubbles forming beneath the surface—occurs when organic materials burn out too quickly during bisque firing.

Preventive measures include controlled drying cycles, proper kiln loading for even heat distribution, and precise temperature ramping. Test tiles help verify glaze behavior before full-scale production. Mastering these variables significantly reduces defects, ensuring higher-quality porcelain artworks.