Having a look through the archives earlier and found verifiable and conclusive evidence of my earliest noodlings, from back in 2012. Seem to remember it being a time of Interbrand, Arduino's, conductive ink and Adafruit! Wish I still had this one. It was A2-sized, with the letters cut out of a sheet of black paper, glued to the reverse of a sheet of watercolour paper, and backlit with small LED's, which would activate with a simple light sensitive circuit, burnt onto an ATTiny85 chip.
