Ah, I see I took the first answer too quickly. Sorry to doubt you Chuck. As for what you guys seem to be calling diazo, which I'm not doubting, I have that in two varieties: Blue LINE and Blue PRINT. I never knew there was a difference. The first time I saw the Blue PRINT, I thought it looked like someone was doing there drafting with a scratchboard knife. Why would anyone put that much lead or ink on the paper, I wondered? Then I found mylars that printed as negative for this purpose. I still wonder why anyone would do this. Anyway, thanks everyone for the input. I'm learning more about manual drafting than I ever will need. As well, I'm learning more about the history of the buildings at this school I'm working at. I've only been there a week and with some of the pictures I've seen, some things give me the chills and a haunting feeling.
This is the school website if anyone cares.