I was fooling around with some cyanotypes this weekend and was stuck with one problem. Printing on curved surfaces. Actually double curved surfaces. I wanted to print on the outside of a bowl. As far as I can see i have to cut the negative, to fit the surface, but how do I get it to stay on the surface ?

Have any of You tried this before and how did You get it to work ?

Unless the curvature is very large, you don't need to cut the negative.

All you need is a good point light source, and there happens to be one conveniently located in the sky. :)

Use clingfilm to hold the negative in place as close to the surface as possible, you might need to play around with it a bit before you find the best fit. Then clingfilm it in place (no more than one layer, or you will get interference and wrinkles), put the whole thing in a dark bag and take it outside. Then expose the thingy without turning the bowl (unless you can rotate it slowly at a rate of one turn per 24 hours, of course). Put it back in the dark bag, and take it inside for processing. :)