Shibuichi

Shibuichi(四分一) is an alloy which can be patinated into a range of subtle muted shades of blue or green, through the use of rokushō treatments. Its name means "one-fourth" in Japanese and indicates the standard formulation of one part silver to three parts copper, though this may be varied according to the desired effect. A 5% silver / 95% copper alloy is also marketed as "shibuichi". A wide range of colours can be achieved using the whole range of alloy compositions, even above 50% silver. 90% Copper and 10% Silver for a dark grey and down to 70% Copper and 30% Silver for lighter greys.