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Raku Ware and Staffordshire Pottery
Raku Ware was originally from Japan in the town of Kyoto and was named after the Raku family during the 16th Century. At this time, the Emperor Hideyoshi had conquered Korea and the native potters immigrated to Japan bringing with them pottery techniques and knowledge.
The pots were produced for the Zan Buddhist tea ceremony and the decorating and firing of the pots were part of the tea ceremony. Bernard Leach introduced Raku into the west after living in Japan and China setting up pottery in St. Ives, England in 1920. It is still popular today, and made almost worldwide. Raku Ware is still produced today by the 14th generation, of the same Japanese family.
Staffordshire was a large and important part of Britain for earthenware production. The first known examples of Staffordshire slipware date back to early Seventeenth Century. Even though lead-glazed earthenware seemed to be established before this time, the market generally went beyond Staffordshire. Butter pots made in Staffordshire were well known for their quality by dairy farmers in England and surrounding areas. Slipwares are named for their decoration with liquid clays, usually poured or trailed onto the pot. Although this was a highly developed technique in Staffordshire it was used in other surrounding areas such as London and Wrotham.
Staffordshire slipware usually has three categories flatware which are plates, dishes and bowls, jugs and lidded pots are classified as hollow ware, and miscellaneous ware includes money boxes, cradles and candle sticks.
Just as tea was important in the development of Raku Ware in Japan, so the Elers brothers who studied salt glazes in Europe and moved to Staffordshire in the 1690s, produced small tea pots, tea canisters, teacups and jugs. They used finely prepared red clay which was thrown on the wheel, and then lathed when leather hard. (Common salt is thrown into the kiln during firing 1200oc to produce a salt glaze)
In Raku any clay that copes with the firing technique must be able to withstand heat shock without warping, distorting or cracking. The clay needs to have particles in it to allow water to escape quickly so calcinated China clay or clay with temper (grog, flint or shell) added to it, is successful. This clay occurred naturally in Japan. Many contemporary potters have favourite clay recipes for their clay bodies when making Raku Ware.
Staffordshire slipware clays usually have trouble withstanding higher temperatures without distorting and warping while stoneware can. It was discovered that when calcined flint was added to the clay, it would allow the pot to withstand higher temperatures and even whiten the overall appearance of the pot. This whitening effect in the pots was adapted as a alternative to porcelain. There was not a suitable white firing china clay as used in the East, found in England, except in Cornwall. The porcelains in the Staffordshire area are known as ' soft paste ' because of their low firing temperature and the clay body was rich in quartz and low in clay with glass frit and lime or gypsum added to get rid of the unwanted iron-oxide colour. Wedgewood developed his cream wares by adding china stone and china clay to the body he was using resulting in a whitish blue strong body known as pearl ware. He also developed coloured clays to imitate stones such as jasper, basalt and onyx.
In the early 18th the firing technique for Staffordshire Ware changed to a two staged firing. The first was on the unglazed pot to produce biscuit ware, which was dipped in a lead glaze and re-fired at a lower temperature. By the end of the 18th century the kilns moved from wood and charcoal burning to coal burning. These kilns* were larger with five or more mouths and a distinctive bottle shaped encasing chimney. These improved firing techniques allowed more decorative styles and improved appearance with hand painting and printing of border designs, figure painting and landscapes becoming popular.
Raku Ware when fired is often spectacular and has uncertain outcomes. The pot is covered in a glaze, placed in a red, burning hot kiln and fired until the glaze has matured, the pot is then placed out of the kiln and is allowed to cool quickly. With that dramatic cooling down period, the glaze crackles, and this obviously gives the pot a broken and smashed appearance. And this can take sometimes less than one hour to complete. Raku Ware firing is a dramatic and involves trauma for the pots.
Originally potters in Japan used raw lead as the main ingredient. However this can lead to lead poisoning. Nowadays, a fritted lead is substituted which is more stable. Glaze must stay on a pot during the firing process and melt from 800oc - 1100oc although Black Raku is fired at 1200oc. Post firing reduction may be part of contemporary Raku pottery. Fuming is where metal salts are sprayed onto the molten glaze of a red-hot Raku pot straight from the kiln. Chemicals introduced directly into the kiln (non-electric) during firing is called vapour fuming and is also possible with Raku pottery. However a smoke finish using sawdust or other flammable product is popular.
Lead was also used in Staffordshire Ware as a glaze but salt glaze was introduced from Europe and a scratched blue, salt glaze ware was also produced using a cobalt blue stain. However the slightly rough surface of the salt glaze a braised silver cutlery so this ware was replaced by cream coloured ware by the end of the 18th century. Wedgewood made the cream coloured earthenware universally accepted.
Raku Ware has regained popularity in the last thirty years because it gives great expression and the excitement of drawing red hot pots from the kiln and smoking in sawdust and unpredictable results suit many potters. It was introduced by Bernard Leach into England in the 1920s and revived by Paul Soldner in the United States in the 1960s. Some of the original potteries established in Staffordshire in the 1700s are still producing pottery today, with many of their items sort after by collectors world-wide. Where Staffordshire is famous for its mass production, Raku Ware is more individual especially because its techniques often produce unexpected results.