The problem with ink made from fairy blood—legendary in the art world for the shimmering colours that exist nowhere else in nature or supernature—is that the ink fades rapidly. “Fade” isn’t really the right term; the ink (blood, remember) sublimates when observed. There is a product called FairyFrame: a picture frame with a liquid crystal shutter that covers the framed image. This IoT device allows owners to use AI face recognition to authorize viewers. The LCD shutter remains opaque unless an authorized viewer is present—no point wasting views of their prized (highly illegal) possession on the chambermaid.
Why am I telling you this? There was a cyber incident at FairyFrame; the names, credit card numbers, and addresses of thousands of FF customers has leaked to the darknet. You definitely should not grab the list and check if there is someone who purchased a frame for their blood “art” near you. Absolutely don’t use their credit card to buy a pitchfork nor any kind of fire-starting devices.