@fansy,
Quote:Chinese speakers of English do not pay much attention to the difference between a seal and a stamp. I myself may say "I used my private seal for making a stamp impression on a painint."
This is what I was getting at. They are used almost interchangeably in English phrases too:
"seal of approval"
"official stamp"
But note, the actual seal, to make impression in wax, is of historical interest/ importance only. Whether we call it a seal or a stamp nowadays, the mark is made in ink by a stamp.
Look up the meaning of "seal"- it was originally used to mark the wax which
sealed or closed a private document (such as a letter) shut. Some nobility/churchmen etc. made their unique imprint in the wax using an embossed finger-ring.