On 2/17/25 09:03, Jon Elson via cctalk wrote: > Teledeltos paper had a silver layer over a carbon layer, and a spark > blew off the silver to expose the black carbon. (I think that's how it > worked, I haven't seen this stuff in decades!) It was used in early > machines for sending weather facsimile maps, for instance.
I think the stuff may still be available in single sheets for physics demonstrations and perhaps for use in kymographs not using ink. I checked up on availability perhaps 20 years ago, but not recently. --Chuck
