Is there such a thing? A couple old forums mention them, but I don't know exactly what they are. I am curious about whether there is a relatively easy and cheap way to make cyanotype enlargements from B&W negatives using sunshine.

I know almost nothing about cyanotypes. The reason I ask is that I don't have a darkroom or an enlarger, but I think it would be a rather neat thing, though perhaps somewhat novelty, to make "blueprint" photos.