Gold plated OCC copper :)
This has proven to be the best material for interconnects, I'm offering it for cheap, please inquire about this stuff. Sonically it's warmer than the silver, while the silver offers brightness. I love the silver on the Grado, but if you're looking for a conservative and "homely" sound with a bump in clarity in all the frequencies, this is really as good as it gets!
If you guys need this stuff for projects, please e-mail or PM me and I'll get it out to you guys, it's enamel coated, so all you'd need to to is braid and win!