I would appreciate any resources to support using BFK Rives 30 x 44" - 280 GSM. Trying to find backing board, or something a bit sturdy to include in a clear acid free bag for storage and transport. Also archival backing boards for framing. Any ideas? I have done an hour of research and 40" seems to always be the maximum. Thank you.
Our Rising Museum Board is produced in larger 48"x72" (yielding 4 out of a sheet). Rising in this larger format is usually sold through the wholesale framing channel. A list of those distributors can be found on the Rising site.
http://risingmuseumboard.com/wheretobuy/
For bag storage you might try reaching out to ClearBags as they produce archival storage bags in all formats.