Vessels made of earth, coated with a glaze and baked are ceramics and are not permeable by light.
Meanwhile, porcelain are very hard and are permeable by light.
These are all generally called Tojiki in japan.
Tojiki are not only for practical use but are often works appreciated for their high art.
In the art of flower arrangement（Ikebana or Kado）and the tea ceremony（Sado）, the very appreciation of the flower vases and tea cups as vessels for their own sake is regarded as important; those arts, therefore, were connected all the more to the development of Tojiki.
Tojiki are also referred to as Setomono, a term taken from Seto city in Aichi prefecture, a well-known production site.
Representative ceramics are Shigaraki ware from Shiga and Bizen ware from Okayama; among porcelains, Imari ware from Saga prefecture and Kutani ware from Ishikawa are famous. 
