Pure, natural "muku" wood

The word 無垢 (muku) originally means “pure” or “untainted,” a sense of innocence and naturalness. From this comes the idea of something unmixed or in its original state. Muku wood 無垢材 refers to timber cut directly from a single log, not plywood or engineered wood.

Though prone to cracking, it offers the warmth, texture, and authenticity of real wood, free from chemical additive. It also naturally regulates indoor humidity by absorbing and releasing moisture with the seasons. I just saw that @genkidesu 's most recent post is about the problem of heat in bedrooms in the summer. Perhaps, "muku wood" in bedrooms is one way to help reduce heat in a room, but it alone cannot relieve the heat of summer. 

Today, and June 9th annually, is Muku Day 無垢の日, but in essence it is "muku wood day". The anniversary was created by Prairie Homes with the aim of promoting the use of natural wood in response to growing interest in sustainable materials, resource efficiency, and long‑lasting housing in Japan’s construction market. They chose June 9th as the anniversary because 6/9 can be read as "mu (6) ku (9)".