reminded me of this http://en.wikipedia.org/wiki/Silverpoint http://en.wikipedia.org/wiki/Silverpoint Given they say "Each pen will be sold with a notebook ma

reminded me of this http://en.wikipedia.org/wiki/Silverpoint http://en.wikipedia.org/wiki/Silverpoint Given they say "Each pen will be sold with a notebook made of "stone paper"" I suspect, just like silverpoint, it doesn't work, or doesn't work well, on any random surface.