Thx for the feedback. If I was to try this what do you think I could do get black rather than brown dye? Would I have to use flowers that are closer to cyan, magenta, and yellow so it is closer to the cmyk color model or does that not help?
Also yeah idk if the contrast problem could be solved.
Trying to do say three layers would then take six hours, so whatever you’re using as a mask has to be super absorbent or reflective to UV (think very thick black paper or tinfoil). Anything else, and your underlying layers are going to bleach somewhat.
Do I need to do it in multiple layers? Also I was planning on trying to use the paper as a replacement for photo paper in pinhole photography with it instead of a mask.