This is a neriage mold made bottle. Made by the retired foreman Fukuyan, who I sat next to during my 3 year apprenticeship. It is an example of using the right tool for the right pot. The slabs, pushed into the mold, help keep the squares of clay together, to form a good bond. The bottle below was thrown as a cylinder and then was paddled and ribbed. Coils were added to the corners to help make them sharp. It was fired in Craig Edward's anagama.