When I had a darkroom, which I don't anymore, the only absolute necessity was a tall stool. I had a very nice one for a while. The funny thing was that while I really liked it, I spent hardly any time at all sitting on it, which I guess put it in the luxury category. :-)
Thinking about it now, I have the sudden urge to search Amazon for something like the one I left behind at one job in 1973. . .
Bookmarks