Homebrew PCBs

1 oz sheet (.00135" thick) in a 12" x 25" for $3.95:

http://www.onlinemetals.com/merchant.cfm?id=129&step=2 

You can probably ask them to cut it into 11" x 25"

1 oz is pretty thin so you might try 3oz, which is closer to paper 
thickness (.00405). The downside is it is quite a bit more expensive

3 oz sheet (.00405 thick) in 12" x 25" for 14.15

I have no affiliation with these folks - just a happy customer.

Cheers,
Bob Welland