Specifically, the seal refers to the original seal, while sealing clay refers to the clay used to cover the sealed property, just like stamped wax on an envelope, while pottery texts refer in many cases to the pottery imprinted with seals.

All of them are of significant value in paleographic and philological researches.

Moreover, as seals usually recorded various historical information, such as personal names, clan emblems, and names of officials and places, they are also particularly valued as important sources for research on history, geography, ethnicity, ideology and cultures.

In addition to academic values, seals have high artistic value as well.

The seals' knobs come in diverse forms and shapes and are regarded as art, and the character structure, stroke arrangement and layout decoration on the tiny square have often inspired calligraphy and graphic design.

Matsumura, who started studying sealing clay in 1987, was actually first captivated by calligraphy. However, instead of writing calligraphy, he found himself more interested in research on calligraphy, and then became fascinated by ancient Chinese writings, such as xiaozhuan (small seal script) and lishu (clerical script).

"I learned from my teacher, who was a researcher at the Tokyo National Museum, that few people in Japan were studying sealing clay and pottery texts," Matsumura recalls. "I was interested in the calligraphy and would like to take up the challenge that few people had made before."

He adds that he felt like he was coming back home at the inspiring seminar with many Chinese experts in this field.