After analyzing glaze shrinkage freckle on cap and pin insulator body observed in manufacturing process,the author attributes it firstly to deviation of body moisture from technological specification,and secondly to low temperature at glazing and thick ink for marking.

By means of chemical analysis,determination of melting temperature rang,polarizing micoscope,reflecting micoscope,scanning electron microscope and X ray, studies the factors concerned, Which result in glaze defect, and proposes some suggestions relevant practical proces

This paper has discussed in theory some common factors,which cause the defects of ceramic products, including glaze cracking,pinhole and glaze crawling with a view to provide reference for troubleshooting glazing defects in ceramic production.

Enamel hypoplasia mostly affected maxillary incisors.