Since some moisture is always necessary for the performance, the artist breathes on the leather and the tuning paper (Choshigami, a small piece of Japanese paper mounted on the back of the leather) is adjusted by wetting with saliva.
演奏にはつねに適度な湿気が必要で、革に息をかけたり、裏革に張ってある調子紙（和紙の小片）を唾でぬらしたりして調節する。