The Daler Rowney's Calli is a calligraphy and India ink made in England. It's an acrylic-based ink designed specifically for calligraphy.
The Calli is actually available in different colours as well, namely Scarlet, Burgandy, Green, Blue, Scarlet, Brown and Jet Black India (the one I'm reviewing). It's also available and sold as a set of 6 colours too.
Warning: Last items in stock!