Why did it take so long to invent movable type printing?

[Brightonian]

Once you have woodblock printing, the extension to movable type seems a natural one with hindsight, yet it took several centuries in both the East and the West. Why so long?

[admin]

Actually, the Chinese did have movable type, made of ceramic, around AD 1000. The problem was that the Chinese language had thousands of characters, which made movable type impractical. In Europe, movable type had to wait on a good alloy which was tough and had a low coefficient of expansion. It was Gutenberg's discovery of such an alloy, of lead, tin, and antimony, that was the great breakthrough.