I like the idea of a paper negative...but I still have to figure the best way to make the slide. If I use something like movie print film, I'd have to buy some, as well as some CD2 developing agent (it's process ECP-2, which is very similar to ECN-2, which I do a lot of, except for the developing agent used). My big question is whether I can make a good "inter-slide" with black and white film, given the color mask of the negative (color movie print film is matched for this, and indeed many of my negatives are on ECN-2 film to start with).
If I can use b&w film for the inter-slide, then the easiest for me might be then to print it onto some imagesetter film to make the negative, as I have quite a lot of that given my rather dormant offset printing business. (if indeed it will print halftones when used as an analog film and printed say, in dektol).
I took a look at the cyanotypes you have on your website - you do some awesome work!