ink pad; stamp pad
Refers to the inked pad used with personal seals (hanko) or rubber stamps. Often a vermilion paste-like ink in a small case.
印肉が乾いてきたので、新しいのを買わなければ。
The stamp pad is drying out, so I need to buy a new one.
朱肉の代わりに黒い印肉を使うこともある。
Sometimes a black ink pad is used instead of a vermilion one.
Compound of 印 (seal, stamp) and 肉 (flesh, meat), referring to the soft, flesh-like pad that holds ink. The exact historical derivation is uncertain, but the term has been used since the Edo period.