The Japanese term for painting with ink is sumi-e. The art of sumi (ink) was introduced to Japan from China sometime around 610. It had been practiced in China since 2,000 BC in other forms. In Japan, sumi-e was influenced by the teachings of Zen Buddhism, and by the monks as well. Many of the monks were very talented painters.
The ink in Sumi-e is very important. Chinese style sumi-e uses a brownish ink, where Japanese style uses blue. Though it appears black, this is only because the ink is so opaque. In Japan, the best ink is considered to come from Nara and Suzuka. The ink is made from lampblack and pine that is burned in a special way. The mixture is molded into a form with glue to harden. When the ink needs to be used, it is ground against a slightly damp suzuri (inkstone). Slate is a common stone choice.
Paper is also very important to sumi-e. You can use rice paper, but most prefer senshi paper which is made from straw in China. Japan also produces a great paper called washi, which is usually made from Kozo or Gampi tree bark. Calligraphy paper is okay to use too, but might make your ink a little too runny. I like Chinese paper because it's a little more absorbent than Japanese, but it's only a personal preference. You can also handmake paper, but since it's so time-consuming most prefer the pre-made.
There are 3 main types of brushes (fuke) used in sumi-e.
Japanese Choryu brush : The most common sumi-e brush. It is normally made from sheep or goat hair. It's very soft and holds a good amount of water.
Japanese Maruyama brush : Made from a horse's soft belly hair, with some stiffer hairs mixed in. It is firmer than the choryu brush and it has a very fine point. This one is great for making thin lines or details.
Chinese Ran-chiku brush : Usually its made of a harder animal hair, like badger. It doesn't hold water as well as the other brushes, but is good for creating thick outlines or rough shapes like rocks.
The most important thing to remember if painting is that you are not trying to necessarily paint the exact object you are viewing. You are trying to paint the character of the object you're viewing. This is why the white space of your paper is also important. It's not blank, it's there to add depth to your picture and to put focus on what you painted.
The brush information was partially taken from Japanese Ink Painting by Naomi Okamoto, copyright 1995. Happy painting!!