Archaeologists believe that seals are used in preference of signatures for personal documents or any transaction requiring an acknowledgement. Based on history, East Asian people work with handprints and fingerprints for signatures by the use of clay then engraved on paper. But handprints and fingerprints were only applicable for a person attaching his signature on the document. On the other hand, seals were used and still often linked with an office or family documents be in need of acknowledgement or authorship.