Indeed, Emil, I don't know all the semantics, and you might be right. Whitey described the plates as "solar" plates, and since he's doing this process at a high school, I bet he's choosing a toxic free technique you describe. And yes... the plate took very little time. I'm trying to figure out which of my images would be well served by Whitey's process, because, yes... I think it would be fun to give it a go sometime.

Here are some links of interest...

http://en.wikipedia.org/wiki/Photogravure
http://www.photogravure.com/