Category:Ceramics

Hierarchy: Materials

From RISDpedia

[edit] Clays

There are many types of clay at the Metcalf store, which shares the same building as the Ceramics department. One of the most important things to keep in mind is for firing (baking whatever you made with clay to make it strong and finished), is that many clays have different firing temperature. So when you are buying clay and want to fire your piece later, make sure you know exactly what type of clay you are getting. They are not numbered on the bags of clay but sort of organized in shelves but sometimes Metcalf gets mixed up.

Coarser clays are stronger when you throw it on the wheel but your hands get sore. Miller clay is white high fire clay (cone 10) and is very fine and compact. It is a little more difficult to center on the wheel but it is a a nice alternative to gray high fire clay, because it's not coarse and it won't hurt your skin. It is a few dollars more expensive than regular white high fire clay. Porcelain is really nice and fine but it is more expensive and can be more difficult to control.

[edit] Glazes

It is putting finish on the pieces after the first firing (bisque firing), then they need to be fired again. Comes in various colours and you can create new colours by mixing different glazes or chemicals. It is really hard to make the exact colour for your piece because the colour of the glaze is affected by the clay of your piece, density of the glaze, where in the kiln you put in and the oxygen flow. So if you are shooting for colour #0084, you will probably not get it.

Toxic to breath in before they get fired but after they are fired, your pieces will be safe to drink, eat, microwave etc.

Practice Clay You can buy clay that Risd grads mix from clay students throw away. This type of clay is cheaper and comes in black bags. It is low fire clay but it is usually not fired.

Red clays like terracotta are low fire also. There is low fire white clay which is fine and easy to practice with. For making vessels for everyday use it is ideal to use high fire clay. This includes (to the extent of my knowledge) White high fire clay (looks gray), Miller clay, and porcelain.