This style of tsuba was made in the Edo period around Nagoya. The general term for all tsuba of this type is Nagoya mono. They were designed in the Goto style of Kyoto and Mino. The plate metal, termed nigurome, is a base metal of katashirome (tin and lead) and unrefined copper (yamagane). This base metal forms the finest shakudo when three to seven percent of gold is added, and the alloy thus formed is properly patinated.