I think you have your own stamp in your house. Nowdays, people usually use signature instead of stamp. In the past, western cultures usually use signiture instead of stamp, however Asian culture use stamp in the past. In this days, they use signiture more than stamp. Korean people use stamp to aproove that they agree on the diplomatic documents or others.

 King and Queen used a stamp called ok-sae. Ok-sae was too valuable. According to the History of Three States(»ï±¹Áö), there was a fight between a two man with a ok-sae. Ok-sae was made up of gold. When King or Queen loose their ok-sae, it was like losing their power.

 Crown Prince have his own stamp, too. It was not made of the gold like his father's. It was made up of silver. It have a same characteristics and same responsibility. Ok-sae was a stamp that they can't loose forever.

 Ok-sae's shape was various. Some were shape of dragon, and other looks like turtle. There were a lot of animals that carved on ok-sae. Now days in Korea, the president still have Ok-sae. And this is used only a few times.