The origin of folded paper gliders is generally considered to be of Ancient China, although there is equal evidence that the refinement and development of folded gliders took place in equal measure in Japan. Certainly, manufacture of paper on a widespread scale took place in China 500 BCE, and origami and paper folding became popular within a century of this period, approximately 460-390 BCE. It is impossible to ascertain where and in what form the first paper aircraft were constructed, or even the first paper plane's form.