Raku, means "Pleasure", "Enjoyment", "Best in the world" and begins in a
tea ceremony in Kyoto - Japan, arriving there with the Zen Buddhist monks
from Chine in the Twelfth Century.
     Tea Originally drunk on ceremonial and religious occasion or used as
medicine. This practice then spend to a wider section of the population.
     Sen  no  Rikyu  (1552 - 1591)  was  a  man of  a  great  artistic  judgement
and one who was  commissioned  to  design  a  tea bowls  and  produce  it  at his
specifications as a Tea Master. These tea bowls  were  carved, not  thrown on the
wheel and  therefore  great  subtlety  could be caught in their structure and
volume in the relationship between internal and external space, each  elements  
of  this ceremony  was carefully distilled,  with  the  purpose  of  creating  a  
situation and  atmosphere  where spiritual self-development could  take  place
and  through  a  quiet focusing of  the  mind, to achieve an  ego-less  state.
     The simple  appearance  of  the tea bowls, the  preparation  and handling of
tea implement, the quiet filterers  light  and the simplicity of the tearoom, its
scents and objects, even movements of the people participating, were essential in
his form of ceremony.
     In this  contest  the  tea bowls  exist  naturally  and  harmoniously  in  which  
the guests could decorate and take  it home with them as a keepsake, The Raku
technique has enjoyed a revival in modern times.
     Best made Raku is made from  a heavily gorged body high in fire clay, then
are decorated  with  a  low-fire  glaze.  Often  this glazes  will  contain  metallic  
oxides  such  as copper carbonate, silver nitrate, ferric chloride, tin chloride,
silver chloride, bismuth sub nitrate copper sulphate, which will reduce to a pure
metal in the process.
     Once   the  glaze  is dry,  the  pieces  are  placed in a kiln, which may be cold
or already up to temperature. It's really  an  experience  and  has  its  own
particular mystery the earthiness of smoked clay,  combined  with  vibrant  
coloured glazes and the necessity to be fired again and again sometimes in
different range of fires and the results are often surprising. A front-loading kiln
is much  better  than  a top-loader for Raku, as the ware must be easily removed
from the kiln when the glaze  is  observed to melt, and the rush of superheated
air that comes out from the  opened  top  of  a  kiln  results  in a rapid  loss of
heat, and can be dangerous as well.
     This process  is also  much  more suitable  for outdoor  than indoor potteries,
due to the toxic fumes generated. The pot  is  removed  up  quickly  from the
kiln  with  long tongs  (wear always heat-resistant gloves  and  eye  protection  
when  opening  hot kilns  and  a  wet towels  in  the hair  and the precaution to
turn off the  power to  avoid  an  electric  shock with  the metallic tongs)  while
the  glaze  is  observed   o  melt,  is  put  on  a  small  pile of leaves, sawdust,
fruit peels, pine needles,  cattle feed,  rise peels,  seeds,  straw, grass and also
newspaper, lying on this and is covered with this materials inside of a metal
container so as to seal the pot in a  smoky and oxygen-poor  environment  
obtaining  a  reduction  atmosphere  because the effects only take place  while
the glaze remains molten. Steel drum with their tops cut off, sized
proportionately to the ware,  works  well  for this. One piece at a time, is for me
the best way to work and in the critical moments with a good friend for enjoy
this play with fire, helps.
     Although  some  sources  advice  a  water  quench,  is not necessary, and  will
 only  weaken the ware, which does best if allowed to cool off in a warm place.
Raku has been the scene of  much  technical an artistic innovations. The link
between the past now exist most positively through the activity and its effect on
the work produce, history and art change as our attitudes change.
   Ceramic Technique Raku
Crackle Raku Glazes
When  a  glaze shrinks  more than the clay body it covers, cracking or crazing  occurs.
Different types of glaze will crazedifferently. As  the glazecontracts, it can  be heard to ping
and shrink. The form will also influence how a glaze crazes. This effect  has  been  used in
the  past decoratively  by  the  Chinese in high  feldspathic glazes.