Here is a proof-of-concept draft I made last night, for the talismachines. The print was designed in Inkscape and laser-printed onto cotton letterhead, then hand-painted over with Bare electrically conductive paint. It includes a coin-cell battery, on-off switch, and white LED from the LilyPad Arduino family. The inverted triangle in the upper-right is an alchemical symbol for blood, and contains a drop of (my) blood.
The magical purpose of the talisman is to give “great knowledge and wisdom in mechanical arts,” and it features the sigil of the Goetic demon Barbas (or Marbas). It shows also the hammer and anvil of Tubal Cain, and a classical symbol for fire indicating Hephaestus/Vulcan. Its practical purpose is to experiment with the media. The proper talismachines will be screen-printed on parchment or canvas, and will include a LilyPad microcontroller for more interesting interactions. I may need to run conductive thread behind the parchment, because the Bare Paint rapidly increases its resistance over the lines.