Calligraphers usually write with black, water-based inks (known as sumi (墨) in Japanese) made from soot mixed with glue. Despite these seemingly simple ingredients, there are many different inks to choose from, each with its own particular qualities.
The inks which are most prized by calligraphers are those made from the soot produced by burning vegetable oils, such as rapeseed oil, sesame oil, camellia oil, and soybean oil, or tree resins, particularly pine resin. The soot from such oils and resins is made up of very fine particles. Inks which contain fine particles tend to bleed less than those which contain coarse ones. Moreover, when inks with fine particles dry, they retain a subtle sheen, leading to better-looking calligraphy. Another benefit of fine particles is that they are less likely to get clogged in the hairs of a brush, which makes cleaning easier and prolongs the life of the brush.
Cheaper inks are made from carbon black, sometimes in combination with the soot particles mentioned above. Carbon black is a by-product of burning heavy petroleum products such as tar, and its particles are quite coarse. As a consequence, cheaper inks tend to bleed a lot and do not have the sheen of more expensive ones.
The glue (膠, nikawa) used in these inks is made by boiling animal and fish skins and bones until they become a jelly-like paste. The quality of the glue largely depends on the care taken in choosing which bits to put in and which to leave out. The highest quality becomes gelatin, which is used in food production. Nikawa is not such high quality, but it does have higher water absorbency and retention properties than gelatin, making it ideal to use for ink.
The production of solid inks
The soot is mixed with hot, liquefied nikawa. Natural plant fragrances are added to replace the smell of the nikawa with incense-like scents conducive to the serenity needed for good calligraphy practice. The mixture is then kneaded by machine before being allowed to cool. The cooled mixture is still soft and malleable because of its high water content. This is split into smaller chunks and kneaded by hand to ensure that the soot particles are evenly distributed.
The chunks are pressed into stick-shaped moulds and allowed to partially dry. After being taken out of the moulds, the sticks of solid ink are lain between sheets of newspaper in boxes of ash for one to two weeks, depending on their size, to remove most of the remaining water content. The drying process is completed by air-drying the sticks for one to three months.
The surfaces of the sticks are washed to remove any ash or dirt, dried again, and decorative brand names are painted on using water-based pigments. The finished sticks are wrapped in Japanese paper (和紙, washi) and packaged in paulownia-wood boxes, both of which help to keep the ink sticks dry.
Keeping solid ink dry is important for two reasons. Firstly, solid ink will crack if it is not dried soon after it becomes wet. To use a solid ink stick, you rub it in a small amount of water on an inkstone. If the ink stick has cracked, large pieces of it will flake off when you try to rub it again. Secondly, because of its organic content, ink will start to go bad if it is left in contact with water.
The video below (part of a charming “making of” series—all in Japanese, though) shows the production of sumi at the factory of Kuretake (呉竹), one of the most well-known manufacturers of ink in Japan.
Using solid inks
Solid ink sticks are used by dipping one of the ends in water and gently rubbing it on an inkstone (硯, suzuri) to produce liquid pigment that can be used for writing calligraphy. When it comes to rubbing solid ink, there is a saying amongst calligraphers.
“Rub your ink like a sick man; grasp your brush like a youth in his prime.”
(墨を磨るは病夫の如くし、筆 を把るは壮士の如くす, sumi wo suru ha byōfu no gotokushi, fude wo toru ha sōshi no gotokusu)
After producing the desired amount and thickness of ink, it is a good idea to wipe as much water as possible off the wet end, allow the ink stick to air-dry for a short time, and replace it in its paulownia box.
If you do not use all the liquid ink you have produced in one session of calligraphy practice, it is probably wise to throw away what is left. If you cannot bring yourself to do that after all your hard work rubbing the ink, pour the remainder into a clean glass jar, put on the lid, and store the jar in a refrigerator. However, be sure to use the ink within one or two days. Once ink starts to go off, it can get quite smelly. What is more, the fine particles in the ink will begin to coagulate into coarser ones.
Liquid inks
Liquid inks (墨汁, bokuju) are made from the same ingredients as solid inks (although carbon black is used more extensively). The kneading of the soot-and-glue mixture is carried out entirely by machine, resulting in coarser particles than those found in solid ink. Preservatives are also added to liquid inks to stop them from going off.
If you choose to use liquid ink, then it is a good idea to use an inkpot (墨池, bokuchi) rather than a suzuri. The reason for this is that the large, sticky particles in liquid ink will clog the microscopic groves in the stone from which the suzuri is made. As a result, when you next come to use the suzuri to rub solid ink, it will take longer to produce the required amount of pigment.
Solid inks vs. liquid inks
This is a quandary for calligraphers. While ink produced from solid ink sticks undoubtedly gives better results, it takes an awfully long time to prepare even a small amount. Liquid inks are relatively cheap, widely available, and ready to use. Some purists maintain that your calligraphy practice should begin with several minutes devoted to rubbing ink from a solid stick, during which time, you contemplate what you are about to write and get yourself into a state of calmness and concentration. Pragmatists, on the other hand, believe that actually writing is a much better use of time.
As with all things, it is a matter of finding the right balance. If you are going to write a lot or a very large piece of calligraphy, solid inks are simply not practical. It would take hours—days, even—to produce the necessary quantity in liquid form. Having said that, solid inks do produce much better results and are therefore more enjoyable to use. Another option worth considering is that liquid pigment made from solid ink can be mixed with high-quality liquid ink to good effect.
For those who are determined to use solid ink, some time and effort can be saved by investing in an ink-rubbing machine. There are a variety available, some of which use a suzuri mounted on a turntable; others simulate the back-and-forth motion of rubbing solid ink by hand. These are very useful, but they tend to be a bit rougher than rubbing by hand, resulting in coarser particles.
Color variations
The different types of soot used to produce ink result in slightly different shades of black and different finishes.
- Soot from pine resin has a slightly bluish tinge. Because the soot particles tend to be larger and of uneven size, ink made from pine resin does not yield much of a sheen, but it does have depth.
- Soot from vegetable oils has fine, even particles, producing the best sheen. These inks also have a wide range of shades, from brownish blacks to reddish blacks to purplish blacks.
- Ink produced from carbon black tends to be pure black, with no color or sheen to it.
Combining the different types of soot in different ratios allows ink manufacturers to produce a wide range of shades of ink (although the differences between them can be incredibly subtle).
Red ink
Red ink (朱墨, shuboku), which is generally used by teachers to write examples for students to practice (お手本, o-tehon) or to correct students’ work (添削, tensaku), is made from the mineral cinnabar. Although liquid red ink is most commonly used, solid red ink is also available.
It is very unusual to see red ink used for a piece of calligraphy because it lacks the depth of tonal variation that black ink has. When you are working on your own original pieces, it is useful to have some red ink to hand: you can use it to make clearly visible corrections to the drafts of your compositions.