The copper bar (110 Copper Rectangular Bar, Unpolished (Mill) Finish, H04 Temper, Standard Tolerance, Inch, ASTM B187) can be found on Amazon. I got the 1/8 inch x 1 inch x 36" which right now goes for $26.99. My DH cut it into 4 equal pieces and then drilled a hole in one end to hang. When I finish a run, I take out the copper bar and clean it up to renew the surface. I only use one in my setup (see picture below).
I found the tutorial by Janelle Zorko (
http://pigeonpointglass.com/electro-tut.html) was a real help. This website -
http://www.hobbies-and-pastimes.com/Electroforming.html - has a recipe to create your own solution. I plan on trying this in the hopes that I don't have to keep purchasing it from Rio.
Good luck!