Stretchers

I am inquiring on behalf of someone who is not on the list:

A very large contemporary painting is in need of a sturdy, rigid
stretcher.  Does anyone know of a vendor(s) who carries metal
stretchers in North America?  If not, can anyone suggest an
alternative material or system to ensure the painting's stability?

Sarah Melching
Pacific NW Paper Conservation Svcs., Inc.
Seattle, WA

                                  ***
                  Conservation DistList Instance 13:9
                  Distributed: Thursday, July 22, 1999
                        Message Id: cdl-13-9-018
                                  ***