Jeff Katz June 29, 2011 11:56 AM This is nothing new. Conductive pens have been around for a long time, ostensibly to replace damaged traces on regular PCBs. I don\'t see how this pen is any different. Filipe Varela June 29, 2011 01:49 PM Where do i order? Austin Brown June 29, 2011 01:55 PM Jeff, that is to repair damaged PCBs, and could be used on paper. But, if the ink your talking about is put on paper, and bent, will its conductivity sustain itself? will the electronic pathway still be intact? Charles Bosse June 29, 2011 02:15 PM What kind of solvent does this use? In the past, effective silver \"ink\" has come in pretty toxic solutions. Facebook User June 29, 2011 03:42 PM @Austin: Yes it will.There are cheap pens at Farnell (Newark Direct) (cheap being 10 to 15 euro) that will leave a semi-hard substrate that may tear in tight corners (though slight flexibility is there). But there are chemical suppliers that have been selling these kinds of gel-based carbon-silver hybrid pens for over 10 years at twice or three times the cost, but these will stay in tact around very tight corners and work perfectly fine on paper, even the more porous sketching paper.That said, this being a normal kind of gel-ball-point I would be interested in sampling it to compare, because there is certainly room for improvement in the ergonomics department. Marco Righetto June 29, 2011 04:01 PM Is it on the market? Bobby Lee June 29, 2011 04:38 PM Austin, yes it will. The pens put out by Caig use silver in an epoxy so it flexes just fine without breaking the circuit. Ken Gilleo June 29, 2011 06:54 PM Circuit writing is very, very old and silver has been a common material because of it\'s unique properties. I had a silver ink pen at one time. Thomas Edison, in 1904, proposed applying silver traces to linen cloth to make flexible circuits and this is documented in a letter. Tom suggested using a silver salt solution and then reducing to pure silver once applied. Gregg Eshelman June 30, 2011 03:52 AM How do you do circuits where one trace has to cross over but not connect to another? Ronald Grover June 30, 2011 08:02 AM Gregg, Try a piece of tape.