Boku-Undo Co., Ltd.

◎ The Producing of "Sumi" Ink Sticks

Sumi is made by kneading together soot from pine and other plants' seed oils, and bone glue, then adding perfume, casting it in a vessel, and letting it dry. It seems simple, but in order to make the most of these ingredients, it is best to use traditional methods by which Sumi was made 2000 years ago. The Sumi made by the traditional methods has not lost its color today and will continue to maintain its color in the future. Sumi is like wine in that it matures over time. High quality sumi continues to mature from 1 or 2 years to five or even more years after it is made. Every day the color tone of Sumi becomes more beautiful. This is what we think genuine sumi is. It is not just black ink, but something that goes on living over many tones of years and continues to deepen in smoothness and richness as it is used.


1 Burning. Obtain soot by burning paulownia oil, rape seed oil, or sesame oil, pine branch and etc
2 Melting. Melt down the bone glue by simmering it in a double boiler for a long time to liquefy it..
3 Blending. Put the bone glue and soot into a mixing machine and knead it together until it takes on the consistency of jelly. This is important in determining the quality of Sumi.
4 Pressing. Knead the Sumi again, this time by hand. Then separate it into one kilogram portions, add perfume, weigh each of them, put them into molds, and press them. Even a small Sumi stick requires 30 minutes of pressing.
5 Ash Drying. If Sumi sticks are dried too quickly after they come out of the molds, they break. Therefore, they are put into ashes to dry. The moisture level of the ashes is deceased gradually. This process continues for seven days in the case of small ones, and 20 to 30 days in the case of larger ones..
6 Air Drying.. Each of the sumi sticks is wrapped in woven straws and hung from the ceiling or left on top of a net in a windless room to be air dried for one to two months. This air drying method is still used today to prevent Sumi sticks from breaking while being used..
7 Rinsing. The ashes are rinsed off Sumi sticks with water, one by one. There are also some types of Sumi that do not need this process..
8 Polishing & Shaving. . Glaze is applied and the Sumi sticks are baked over hot coals. Thus, the surface is softened. Next, Sumi stocks are polished with clam shells. (Only for star marked Sumi called ( "KOHKA-BOKU") Then, Sumi sticks are paired off around the edges..
9 Coloring. 3 to 7 days later, the Sumi sticks are dried again in order to remove any excess moisture. Then they are colored slightly in gold, silver, and other colors. Since our company is concerned ultimately with preserving the color tone of each Sumi sticks, we avoid coloring them too much..
10 Packing . After these steps are completed, Sumi sticks are wrapped in paper one by one, put into paper or wooden boxes (paulownia wood keeps the humidity at a specified level and removes moisture from Sumi sticks after it has been used), and delivered.
Our company performs product tests before coloring Sumi sticks to examine the quality and color tone. We wait for the Sumi sticks to mature into a fixed color tone, 6 months for small sizes and several years for larger high-grade Sumi sticks. Then we proceed to step 8 above.
As mentioned above, Sumi is made from soot and bone-glue, but the quality and color tone of Sumi differ a great deal depending on what kind of raw materials are used. One kind of materials can produce no more than one kind of Sumi. Each kind of Sumi is made from a particular kind of soot and bone-glue. No matter how good soot one may have, if one does not have the matching type of bone-glue, one cannot make Sumi from this soot. In the same way, if one does not have soot that matches the bone-glue, one cannot make Sumi from the bone-glue. We continue to examine possible combinations of bone-glue and soot using thousands of raw materials..
The History of Sumi
It is said that "Sumi" came into existence in Early Han China (206 B.C.-AD.8), but even before that time something similar to Sumi was made. Unlike today, "Suzuri" (inkstone) was not used, and paper was not written upon. Rather, wood was cut into small boards and used in the place of paper. Even rough boards seem to have sufficed. The shape of Sumi was spherical so that it could be used after being dissolved in water. During the Later Han Dynasty (25 -220 AD.), paper was invented and written upon with a "Suzuri" and since this was easy to use, it became the prototype for today's Sumi. In later Han China, the source of Sumi changed from "Yubi", named after the pine soot production center, to Sumi, and therefore, we came to call Japanese ink stick "Sumi" as well. According to official records, Sumi was first brought to Japan approximately 1300 years ago by Yubi, a Buddhist priest from Yurai (South Korea). However, there is also a theory which clams that sumi had already been imported at that time. The question is why Nara (our town) became the center of Sumi production in as early as the 7th century.
At that time, Nara was Japan's central city in terms of politics and culture, and functioned as the national capital. During the period when literacy was not yet common Buddhist priests were the primary group of people that used written language and Sumi as well. Consequently, Sumi-making began in Nara, where there have been many Buddhist temples.
Even after the capital was moved to Kyoto, the temples remained in Nara along with sumi. During the Kamakura period (AD 1192 - 1333), purely Japanese-style sumi, was made for the first time from wick and soot, and called "Yuen-Boku". As the Edo period (18th century )there were 38 sumi makers in Nara alone, and the 13 makers that commercialized after the Maiji restoration (1868) and still continue to make sumi today produce six million sumi9 sticks annually, or 90% of the entire nation's sumi in Nara alone.
Our company, Boku-undo, was established by Kyubei Sumiya in 1805 under the name GOBOTOH, but changed its name to Matsui BOKU-UN-DO in 1900 and has operated under the same name ever since. We chemically analyze composition of soot and bone- glue, and make Sumi sticks, knead Sumi and liquid Sumi which have unique tones of color that meet the needs of calligraphers, painters and all kinds of artists. We have led other companies in this field throughout the Post-war era, and will continue to do so in the future. We plan to devote ourselves to research and utilize constantly advancing modern technology to make high quality products, hoping that we will develop from an Asian company into a global company,