What is Sumi

Traditional Japanese black tattoo ink

Since the beginning of traditional Japanese tattooing in the Edo period, Japanese tattooists have used ink block of calligraphy for shading.
There are many types and the quality changes greatly.
Among them, the highest grad ink block has no impurities, has a completely neutral pH value, and is harmless to the human body.
It has been 400 years so far, no one had allergic or infected by ink block. The black ink made with it is very finely grained and it will become beautiful blue-black on the skin. Producing black ink from ink block requires highest quality ink block and ink stone(Suzuri), technic and patience.

As time goes by, tattoo ink companies developed high-quality black inks, and some Japanese tattooists also started to use it. There are changes along the times. 
There is many choice of tattoo black ink for tattoo. But Japanese Sumi is still one of the best quality ink.