Circuits printed on paper are the next big thing among makers. Flexible, a bit more eco-friendly and offering the possibility of writing between components, the most promising of these prototypes use conductive ink. This ink is practical and works quite well, but is very expensive. A 10ml tube costs around 10 dollars on the online components store Adafruit.
Brian McEvoy took up the challenge and got a rather satisfying result, for which he posted the recipe on the Instructables website. The experience turned out to be closer to cooking than to electronic engineering.
Brian uses mainly graphite powder and acrylic paint. For him, these ingredients offer more probing results than charcoal or aluminum powder. As is often the case on open source project sites, the comments are just as interesting as the post. The debate is currently focused on the development of submersible conductive ink… Brian is on it.