|
RAKU
is a firing technique that was developed in 16th century Japan for the Japanese
tea ceremony. This ancient technique of firing pots to a red-hot state, then
cooling them quickly, is still used in RAKU firings today.
While the pots are still
glowing orange with molten glazes (1820ー
F or 1000ーC),
they are pulled out of the raku kiln with long tongs and placed in a cooling
environment - in a metal bin filled with leaves, sawdust, or other combustible
materials (reduction), in a bucket of water or in the open air (oxidation).
Reduction・refers
to the act of depriving oxygen from metal oxides used in metallic glazes by
creating flames that eat up the oxygen supply in the surrounding atmosphere.
Oxidation・
on the other hand,
introduces oxygen into the metals. Flames dancing around pots that have been
placed into a reduction atmosphere create natural patterns of copper, red, gold
and orange colors unique to each individual pot, never to be repeated.
Oxidizing・the
pot, subjecting the pot to water or air, will produce more blues and greens.
White crackle glazes have no metal oxides (therefore white) and are designed to
crackle・with
sudden changes in temperature. Contact with cooler materials, such as sawdust or
air, causes the glaze to shrink more quickly than the pot and the crackles
become more visible when smoke in the atmosphere impregnates the exposed clay
body.
Glazes will be shiny or matte
depending on the glaze recipe. Unglazed areas will usually turn black from the
smoky reduction atmosphere offering many possibilities for wax resist and
masking designs.
RAKU is a low-fire technique.
While our RAKU pottery uses glazes that are lead-free and safe for functional
use, it is more porous and less watertight than stoneware and perhaps best
appreciated as decorative ware. Foods containing acid or vinegar will change the
copper colors. RAKU should be hand-washed delicately and kept away from extreme
temperatures.
|