media for 2 sided imposition proof

[Midstate-Tamara]

We have been using regular printing paper to print 2 sided imposition proofs to our 44" wide epson 9880. (45 x 35-I think) that we cut to 44 inches wide. Our paper suppliers are telling us that this wide a sheet is no longer being made, so we need to look for alternatives. It doesn't have to be contract quality, just good enough for folded mockups, at least 42" wide.