There is a chance of slight black spots/uneven pinhole glaze in the process of ceramic production, which is a normal phenomenon, not a flaw or a quality problem, but the result of natural raw materials and manual operation. Ceramics from raw porcelain clay enamel to firing need to go through dozens of processes and are manual operations, unlike one-time molding glass, stainless steel, plastic and other materials can tend to be flawless. If you like the diversity of ceramics, please accept the natural properties of this material, thank you for your understanding!