Radiocarbon age of the kohitsugire calligraphy and the kiwamefuda certificate

Kohitsugire are ancient paper sheets with elegant calligraphy. They were originally leaves of ancient manuscripts written mainly from the 8th to the 15th century. Old manuscripts are rarely discovered as complete books; therefore, kohitsugire can be significant materials for historical studies if the written ages or the calligraphists or both are known. Most of kohitsugire have kiwamefuda certificates which identify the calligraphists. This is also a clue about the written age. In this study, we determined the written ages of kohitsugire from three viewpoints: radiocarbon dating, calligraphical investigation and the kiwamefuda. Comparison of radiocarbon age and the calligraphical evidence of each kohitsugire give fair agreement. The results are, however, in obvious conflict with the age of the calligraphist noted on the kiwamefuda, and showed the doubtful reliability of kiwamefuda.