I received the following comments from a reader named Glenn Beard, who presents objections to my suggestion that East Asian printing with movable metal type could have influenced the development of similar printing during the European Renaissance. If you read my article you will see that it does not depend on direct European contact with Korea because the vast Mongol empire connected West Asia and East Asia and provided efficient cultural transmission to from Korea to Turkey, which had abundant contact with Europe. The invention of paper traveled a similar route from China to the West. I discuss this process in some detail. As for the specifics of the manufacture, I think this is a better argument, but we should distinguish between technology as a concept and the specifics of its implementation — besides cast bronze type East Asians also experimented with baked clay type cast in iron forms and with tin type (the latter referenced in a document from 1313). The director of the Gutenberg Museum in Mainz has called the possibility of Asian influence on German printing an open question.
Mr. Beard writes:
I read your article on Korean printing, and I would like to point out that evidence strongly points out for an independent development of metal moveable type by Gutenberg. Both the type of metal Gutenberg used and the method of manufacturing the type are vastly different from the Korean method. Had the Korean inspired Gutenberg, then his metal type should have first been made of bronze like Korean type, but that is not the case. There is no evidence that bronze moveable metal type was ever used in Europe.
Also the way the moveable type was made was totally different. Gutenberg used a hard steel punch to form molds in metal plates, while the Korean used wooden punches to form molds in sand. The methods are quite different. Plus, there is the issue of both the distance and short amount of time. Korea, unlike China, was not a country that Europeans had a lot of contact with or trade with at that time. There is no indication that Europeans were traveling around Korea at that time either, or that there were any Europeans who could speak Korean. Also, Gutenberg was a craftsman in the middle of Europe, and was very unlikely to have been in contact with anyone who had contacts with the Far East. There is no evidence that he had any dealings with scholars, merchants who traveled to China, or anyone else who would have been in a position to learn the art from Korea or China. All evidence strongly points to an independent invention by Gutenberg, and the simple fact that Koreans happen to invent a form of metal moveable type slightly earlier is no support for the idea of his having learned about metal type from the Koreans when compared to all the contrary facts.