kuroji
Commonly 'inku,' or in the case of India ink, 'sumi'.
it is called calligraphy
The Japanese word for ink is インク (inku)
L'encre noir =D
Tobiko is flying fish roe. If it's black, it has probably been mixed with squid ink.
its kuro
kuroikokoro
Kurotsuki
Kokushibyou
kokuchou
kuroari
Kuroi sora is black sky.