Raku Firing
"Raku literally means happiness"
          Raku, the firing method, originated in Japan.  This method flourished in the 16th-19th centuries.  Raku was used to create bowls for the Zen ritualistic tea ceremony.
The process was modernized in the 1960's in the Western world by adding a post-fire reduction.  Today's Raku firing is a very dramatic experience.
          The process begins with the application of hand-mixed glazes which contain different metal oxides.  The glazed pieces are loaded into a specially-built kiln that is heated with a propane torch.  The lit torch pushes approximately 200,000 btu's of fire into the kiln.  When the kiln's atmosphere reaches between 1,600-1,850 degrees Fahrenheit, the torch is turned off.  The red-hot pieces of pottery are immediately removed from the kiln with special tongs and placed into reduction containers that are filled with combustible materials such as straw, sawdust and paper.  Once the combustible ignites and the flames dance around the pottery, the reduction container is covered and sealed.
          This starves the fire of oxygen from air, leaving the combustion no choice but to utilize molecular oxygen from the glazes and clay body, leaving bright metallic ion and irridescent luster behind.  Reduction also turns unglazed clay body black.  
          This firing method is very stressful to the vessel (as well as to the artist), as many pieces are lost during this final stage of creation.  The pieces that survive thus become very precious.  Raku-fired pieces of art are not intended to hold food or liquid.  Most often they used decoratively;  however, if used for a vase, you may insert a plastic or glass container.  Because of the chemical reaction, I recommend displaying Raku out of direct sunlight.

Pit-Firing
"Flame-Painted Pottery"
          Pit-firing is a primitive way of firing clay.  This process was used by many different ancient peoples and has resumed in popularity due to its natural beauty and unique process.  It is actually done as it sounds, in an outdoor pit in the ground.
          This process uses "no glazes";  the colors come from the fire, and what I put into the fire.  The pots are buried under several layers of wood, sawdust, straw, dog food, and other combustibles.  The fire is ignited and burns for several hours.  Temperatures in the pit may reach 2000 degrees Fahrenheit.
          When the fire burns down to red hot embers, the pit is covered and left to cool.  The pots are removed from the ash and soot, finally scrubbed and polished.  This is when you really appreciate the individuality of each flame-painted piece of art.
Pit-fired pieces are not intended to hold food or liquid.  Most often they are used decoratively.

Smoke-firing
          Smoke-firing is another primitive way of firing pottery.  This process uses "no glazes";  the colors come from the smoke of fire.  Smoke-firing is less intense than pit-firing.  This process has a different look and feel, one that offers a soft patina which gently envelops the piece.  You can see the movement of the smoke in the soft and dark hues.  The colors can vary depending on the combustible material used;  it can be soft tans to warm browns and yellows, from soft blues to even black.  
Control of the depth of hues can be achieved by the amount of oxygen allowed to enter the firing chamber.
          Some pieces are embellished with hand-carving, then accentuated with stains made of various oxides.  The final stage of smoke firing softens the designs, which gives it a elegant and natural feel.
          Many people ask the difference between pit-firing and smoke-firing; it is the intensity of heat.  Pit-firing is fired below ground where the pieces are buried among the red hot embers, which come from wood, straw, sawdust and other combustibles.  Smoke-firing is above ground, fired in a brick chamber.  The combustible materials used are much faster burning and the chamber allows for oxygen to enter.  This creates a much less intense firing atmosphere, which develops the soft hues of smoke firing.