ROBUCHI 炉縁 (hearth frame):

Shin- shin nuri on hinoki
Gyo- all other nuri; maki-e designs in gold and/or colored lacquers
So- kiji (wood)
What robuchi to use in which room:

Hiroma – makie (sometimes shin is seen)
Yo Jo Han -kiji, makie, shin
Koma – kiji
A. wood- kiji 木地

Since the hearth evolved from the kitchen fire pit (irori) the earliest robuchi were likely to have been plain wood. In Rikyu’s time, the robuchi were used wet, araibuchi “washed hearth frame”, and the wood he prefered was sawaguri, “swamp chestnut.” Other woods include plum, stripped persimmon, zelkova elm, Chinese woods, cherry, pine, paulonia, cedar, Kitayama cedar log (maruta 丸太), bamboo etc but almost any piece big enough can be used. Robuchi are also made of old wood (kozai) from temples, shrines, teahouses, etc. Wood robuchi may be used in the 4 1/2 mat and must be used in smaller, koma tearooms.
B. lacquer

The most formal is hinoki wood base covered with shin nuri; other lacquer finishes include kakiawase, ijinuri, tamenuri, shunkei, seishitsu, shu’nuri, and ikkanbari styles of lacquer. Maki-e and colored lacquer designs have been used since Rikyu’s time. Lacquer robuchi are divided into two catagories: shinnuri and maki-e’ed. Shinnuri are only to be used in 41/2 mat rooms. Those decorated with maki-e may be used in 4 1/2 mats and should be used in larger rooms. design-robuchi are not made with mitered edges. Makers – Nakamura Sotetsu, Risai, Ikkan