Possibly the most popular handcraft in the nation, pottery has made amazing strides on both professional and hobby levels since the end of WWII. There are a lot of reasons for this growth, but the foremost reason may be that the process of making pottery is exciting.
Clay itself is essentially granite-type rock which has, over millions of years, decomposed into tiny particles. There are many kinds of clay, but some of the more commonly used ones are stoneware, earthenware and porcelain.
Stoneware is usually made from several natural clays plus alumina and silica. When fired, it becomes hard and almost glasslike, able to hold water without being glazed. It generally turns out light gray but may also be tan or even somewhat reddish.
Earthenware is usually made from a natural clay and is low fired, as compared to the high firing temperature required for stoneware. Earthenware must be glazed before it can hold liquid. After firing, the color is usually buff or read. Earthenware is mostly used for industrial tiles, but can also be made into decorative and functional pieces.
Porcelain is made from kaolin, ball clay, feldspar and flint. It is white and translucent and requires the highest firing of all pottery wares. It is not very plastic and requires some skill to work, so it is not recommended for beginners.
Essentially, the process of making pottery revolves around the firing process. After you have finished making your pot or figurine, it must be allowed to dry completely so that all moisture is gone from the clay. It is then put into a kiln which is heated to temperatures ranging from 1200 to 2300 degrees F, depending on the type of clay you used. This is called firing, and the goal is to heat the elements in the clay to the point where they fuse. The color of the clay changes during this process. What was once dull gray becomes an appealing buff, tan, dark red or pure white. This first firing is called the bisque firing. Fired clay has a matte (non-shiny) surface. The glossy surface you see on pottery Is called glaze.
Glaze puts a layer of glass crystals on the surface of the clay. It is both decorative and useful, since it waterproofs the vessel. Generally, glaze is applied to the fired pot as a liquid. When the pot is fired again, the glaze melts, forming a thin layer of glass. There are innumerable kinds of glazes which produce endlessly interesting results.
Raku is a method of making pottery developed by the Japanese. The word Raku means enjoyment, pleasure, contentment and ease; however, making Raku work is dramatic and exciting, and also has the highest risk of breakage as the pots may explode during the firing process.
In Raku, vessels made of high fire clay are first bisque fired. They are then glazed with low-temperature glazes having a special composition. The pot is allowed to dry thoroughly. A kiln is heated to somewhere between 1500 and 2000 degrees F, and the potter uses long-handled tongs to put the pot into the red-hot kiln and leaves it inside until the glaze melts. This is usually between a few minutes and an hour, depending on the kiln temperature and the kind of glaze used. Progress is checked through a hole in the kiln. When the pot looks shiny and wet all over, it is removed from the kiln with tongs.
The Raku object is then either placed directly in cold water to cool it instantly, or it can be plunged into a large container full of combustible material such as leaves, newspaper, wood chips, hay or sawdust, and then placed in water to cool. The latter method results in markings and smoking on the piece which gives raku its distinctive look.
Pottery is one of the most challenging of the hand arts, and also one of the most rewarding. It takes years of practice to do it well, but creating fine pottery is well worth the effort required.
Rebecca Woodside
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Where are classes offered in NE Ohio in Raku firing?