Elina Gor asked for sources about the origin, in origami, of paper that's
colored on just one side.
This is the only reference I have about it: "Japanese also started to produce
origami paper, a square of Western paper colored on one side, because of the
needs of kindergarten to teach Fröbelian
Interesting. That is in line with Kunihiko Kasahara’s reference in his book
Origami Omnibus which I mentioned yesterday to Elina’s question: "In the late
nineteenth century, a paper dealer in the Yushima district of Tokyo imported
colored papers from Europe, cut them into small squares, and sold
