The Japanese Incense Wood is called "Jinsui-Kohboku (Aloeswood or Agarwood)" commonly known as "Jinko".
It is not a tree simply grown and found.
Its appearance is like a dead piece of tree.
It has a relative density and sinks in the water, thus called "Jinsui", meaning "sink in water".
I am sure everyone has already seen resin dripping from a pine tree.
Trees secrete resin to protect themselves from cuts.
Jinko is a resinous heartwood that forms in Aquilaria, a plant from the Thymelaeaceae family, native to southeast Asia.
When the trunk of this tree is damaged by a typhoon, eaten by insects, infected by a disease, or buried in the soil, it secretes resin where bacteria form a colony. It is sometimes intentionally damaged in order to get Jinko.
It is not an easy task to find such trees even in the vast tropical jungle.
Not many trees have such quality of resin and it takes decades before the resin become big enough.
It can be heavy, hard, concentrated, dark colored, or stripe patterned and its smell varies depending on its characteristics.
Good ones are very rare and precious.
Jinko was valuable since the ancient times.
"Kyara" is the highest quality of Jinko/Agarwood and its price can be more than 10,000yen per 1g, more valuable than gold.
In the old times, the grading of incense wood was categorized by country of origin (six different countries). However today they are categorized by their smell characteristics (based on five tastes). The name for grading "Rikkoku-gomi (six countries-five tastes)" remained the same.
Kyara, Rakoku, Manaban, Manaka, Sasora, Sumotara are the six types of Jinko. The paper on the picture above is used to wrap big pieces of Jinko. During the actual Kodo ceremony, the piece used is much smaller and is wrapped in a more delicate way with various devices.
Ogata Korin, famous for his painting "Red Prunus and White Prunus", has also created several designs for incense wrapping.
The tiny piece of Kyara wood below the big piece (on picture above) was sliced to place on the incense burner. (It might be a little too small. It is very hard and difficult to slice).
Because it is so precious, it is said to slice it like a "Babi-funsoku (horse tail-mosquito leg)". However different schools have different styles. In my school it is usually sliced a little bigger, about 5mm square.
In the Kamakura period (1185-1333), Kodo became more popular and its style gradually changed. Agarwood itself was used during ceremonies as before, during the Heian period (794-1185), agarwood was also playing an important role but many other different materials were used as Kodo was reserved to aristocrats who had deep knowledge and techniques to mix ingredients.
The compound of all these materials is called "Neriko".
Their appearance is like a tiny black medicine ball.
The compound materials can realize a variety of smells.
"Takimono-awase" is a graceful fragrance play including "Waka (traditional Japanese poetry)", which appears in the famous "Tale of Genji".
I hope to introduce it in another occasion...