紙一重 (kami hito-e)

[Bob1]

Today on a popular Sunday morning classical music program on NHK, they had amateurs conduct an orchestra for short pieces, and afterwards a professional conductor made comments. After a comedian conducted, the conductor complimented him on how effectively he used his eyes to conduct. The comedian replied 「紙一重」(kami hito-e), which my wife explained to me was a self-deprecating idiom suggesting that on the flip side of his eyes lurked only craziness. Although it is not a yojijukugo, it seems to be a very interesting Japanese idiom, derived from the counter for layers of clothing one might wear with a kimono. I still don't have a good handle on it, but perhaps this could be thrown into a yojijukugo-type culture/language lesson.