Bungbox Blue Black is also known as 4B is a Sailor ink made exclusively for a fountain pen store located at Hamamatsu, Shizuoka. Bungbox has a series of inks, 4B is the deep dark blue ink of the series. The bottle is a vase shaped glass bottle. The label has 4 bees (a pun?) on it and it looks almost handmade. I am sorry to say that it is not easy to get a hold of Bungbox inks. Plus, it is anything but afforadable.