Stoneware

Stoneware is fired to a high temperature (about 2200 to 2350 F.).  This allows the clay to become vitrified (glass-like).  Some of the ware is fired in a reduction atmosphere (reduced oxygen) and some in an oxidation environment.  This changes the character of the glazes.  Certain ingredients produce one color in reduction and another in oxidation.  I use no lead in my glazes, so the ware is safe for all food.  It can be washed in the dishwasher or used in the oven (don’t heat or cool quickly or it can crack). Do not use on the stovetop.

Salt Glazed Ware

 This interesting effect is achieved by introducing ordinary salt into the kiln just after it has reached the maximum desired temperature.  The sodium instantly volatilizes and forms a thin glaze coating on the pot as it combines with the silica and alumina in the clay.  The other ingredients in the clay body (notably iron oxide) also affect the final result.  The more iron, the darker the glaze.

Raku Ware

Raku ware is fired a special way.  The bisque ware is first painted with special Raku glazes and allowed to dry thoroughly.  Then the ware is placed in a kiln and brought up to temperature quickly (about 1850 F.).  When it is red hot and the glaze melts, the kiln is turned off and the red hot pots are removed with tongs and put into a container filled with leaves or newspaper or other flammable material until they ignite. The container is then covered tightly until it stops smoking (usually about 20 to 30 minutes). This is when the glazes come alive and take on a personality. The smoked pots are then plunged into cool water to set the colors.  Many glazes have copper in them that will react in different ways depending on the amount of oxygen available.  The results are unpredictable and never exactly the same twice.  This is what makes the Raku process so exciting.

Because the clay is not fired hot enough to vitrify, Raku ware should not be used with food or water.