AbstractExperiments were conducted to find a simple, adequate means of specifying glaze consistency. Tests showed that the amount of slip clinging to a glass plate after it is withdrawn from a reservoir of slip (known as its coherence value) was directly influenced by such factors as amount of water, clay content, and age. These factors are commonly thought of as governing the working quality of the slip. Surface tension has little apparent relation to the working qualities of the slip. Examination of the fired glazes revealed that a distinct coherence value separated good glazes from poor types. A total of 110 pieces was fired; of these samples, fifty‐two were glazed with slips having coherence values above 0.04 gm. per sq. cm. Only three of the fifty‐two samples were satisfactory; the remaining fifty‐eight were coated with slips with a coherence value of less than 0.04 gm. per sq. cm. Only nine of these were defective in any respect and most of them were in the region of 0.04 gm. per sq. cm. coherence value.