CRISTALIZACIONES - GLAZES
Crystalline glazes contain zinc and titanium oxides which cause the crystals to grow. When the heat is raised, the glaze becomes fluid and forms the distribution of the crystals on the pottery. If you have decorated the inside of a basin, all the crystals will fall to the centre and form a solid thin layer of coloured glass with the crystal effect inside it. For the inside of a basin there is no danger of the colours running, but for a pot or the outside of a basin precautions should be taken to ensure they do not run off and fuse into the kiln shelves.
Photos by Concha Martín Soriano