In old Japan, bamboo was used in the frame of the thatched roof. Because,  bamboo is light and elastic material.

Smoke from the fires in the room below would rise to the ceiling. For 150 years or more, bamboo would soaking in the smoke.As the result,bamboo turn to distinct glossy deep brown colour.We call it Susu-take. 

It has the light brown part. The bamboo was tied with rope.It is the pattern of the knot.This pattern is called Keshiki,namely "sceanery".

Each pieces has completely different Keshiki pattern.They are completerly unintentional.

Only the many years can produce the "sceanery".