In Europe crystalline glazes used on porcelain were developed in Sevres and Copenhagen in the mid-19th century. They became particularly popular during the period of Art Nouveau. These glazes, which have a high content of zinc oxide and a low content of aluminium oxide, become oversaturated in the course of cooling and thus gradually crystallize. Crystals up to 10 centimetres can develop in attractive, two-dimensional shapes. The different phases of crystallization result in varying shapes and colours.

To add colour to crystalline glazes metal oxides - cobalt, iron, copper, nickel, chrome, etc- are used. Glazing and glost firing require particular attention and great expertise as a number of requirements need to be met at the same time, if a good result is to be achieved. Crystalline glazes are therefore among the glazes most difficult to control.