Mayco Raku glazes are designed to develop beautiful metallic lusters and crackle patterns when fired according to raku firing processes. There are several methods and many nuances to raku firing - for our purposes here we define raku firing broadly as the processes of firing an earthenware body and glaze in a kiln, removing the ware from the kiln after it has reached proper temperature, placing it in a container of combustible material and enclosing the container to reduce the oxygen in the container.