Sumi Paints by Kuretaki Zig
This is a grouping of six blacks. They will create deep Sumi ink-like colors. The paint is thick and goes on smoothly. If you have ever used walnut ink, think of these as cousins. Monochromatic with a hint of red, blue, green, yellow, violet and brown, they are stand alone or use in tandem. The granulate only slightly, but they mix well with the Tambi Granulating colors! As with the Granulating colors, paper matters. I am finding some of the mixed media papers have a better result as compared to cotton watercolor paper. Walnut Ink swatch provided for comparison.
Find them on most fine art supply websites or stores.