Di mo

The dimo (Chinese: 笛膜; pinyin: dímó; lit. 'di membrane') is a special membrane applied to the transverse Chinese flute called dizi (or di), giving the instrument its characteristic buzzing timbre.

Dimo, made from the tissue-thin membrane from the interior of a specific variety of bamboo, are supplied as tubular sleeves. Only a small rectangle is needed at a time, so for application, a small section is cut off the end of the di mo sleeve, and that small tube is cut open to make a rough rectangle of flat membrane.

The Korean transverse bamboo flute called daegeum has a similar buzzing membrane. The Korean sogeum and junggeum, Vietnamese sáo, and the Thai khlui also once had membranes, but these are not used today.