Are the 'black spots' mentioned in the white porcelain tableware descriptions a product defect?

While the base is pure white, the spots that emerge on it are dark black. Generally, the clay used to make ceramics or the glaze applied to the surface contains trace amounts of iron components. When these components are fired while enduring high heat inside the kiln, they rise to the surface and remain in the form of small spots. While they blend in easily on dark ceramics, on white porcelain, even small spots or traces of glaze clumping stand out much more clearly because the base is bright and white^[1].

It is not a defect^[2]. According to the product descriptions of HORIE TOUKI, the h+ rim plate may take on a light yellowish tint around the rim during high-temperature firing or develop black spots and glaze clumps on the surface^[3], and the white porcelain food container may also have noticeable black spots and glaze marks due to material characteristics^[4]. The brand considers these inherent characteristics of ceramics and does not classify them as product defects, and applies simple change-of-mind criteria rather than defect criteria even when processing exchanges or returns^[5].