I guess this is less messy than copper prototyping (acid etching/gantry ablation/vectorboarding), but silver is more expensive, ~100x.<p>Also, -1 for "help start the home PCB printing revolution." Hobbyists have been making home PCBs for longer than I've been alive. It's not a revolution. Not that many people really want to do this. They could right now with copper, but the range of useful things you can build at home is limited, because having a circuit board is only 1/10th of the problem. Further, prototype services like <a href="http://oshpark.com" rel="nofollow">http://oshpark.com</a> offer high-quality services, including double-sided boards.