Digital BW, The Print

I am about to have a show of 40"x51" prints that were printed on
PhotoRag 308.  I have 
had one test frame made with the print floating.  The test print was
a horizontal 40"x51"
so the curl of the paper was most pronounced on the right and left
side of the print.  This 
made it very difficult for the framer to float the image without it
bowing awkwardly.  Does 
anybody have method of taking the curl out of roll paper (flattening) without
mounting it?

Appreciate any advise!

-Michael
www.michaelfaye.com