Dochu copperware is made of a specially alloyed copper sheet, first annealed
then made into the form of a utensil. The alloyed copper sheet is placed on an
anvil and is skillfully hammered or chiseled. Engraving and small metal fittings
are applied to the surface of the utensil, which is then smoked with rice straw
to fix the resin. Finally,it is polished with oil and fat so that tsuchime (the hammer
patterns) show beautifully. To make tsuchime, it is hammered thou-sands of
times; over ten thousand hammerings total are required for each work. This work
demands a great deal of patience.
 Dochu utensils, Whether vases, ornament trays, pots, tea ceremony utensils,
cake servers, or whatever they are, change to dark subdued tones from their
original copper red, as time goes by. Thus a gracefulness emanates from them.
 The origin of dochu dates back to when Lord Asano moved to Hiroshima
from Kishu Provincei (now Wakayama Prefecture and part of Mie Prefecture).
He brought to Hiroshima a copper craftsman, Kiyoshi, who was immersed in his
work day and night. The lord dubbed him dochu or Copper-worm. With the
lord's protection given to dochu work, the technique developed, but it died out
late in the Edo era.
 In 1902, the technique was again studied and restored by Takuro Ito, and it
continues to this day.