For more about the kite culture of Weifang, try this interesting article with good pictures. Rather than quote it, I'll just provide the link. We saw a lot of kites in Weifang, unfortunately though, not many that were actually being flown! But we did go to the kite museum and saw a lot of beautiful kites in a beautiful building, pictured above. Kite-making in the area goes back thousands of years. As they explained at the museum, kites were used for military purposes, including psychological warfare and signalling, in ancient China.
The large kite below left has whistles built into it. And those little bedroom slippers are in fact a kite!