I am still looking for the easiest method for mounting without having to invest in expensive equipment for dry mounting of 40x60.
I have printed and mounted a several dozen 40x60 prints. For that size I prefer
the CODA Mural Mounts, with a UV-inhibiting laminate on the print. This mounting/laminating is perfect when the artwork is displayed in a public area such as waiting rooms, public hallways and conference rooms. They are light weight, mount easily on a wall, and can be easily cleaned.
The artwork that is displayed in this manner is now 10 years old and shows no sign of degradation due to adhesives or environment.
I realize this aesthetic may not suit you, but at that size, I found the increase in size & weight due to a matte board, frame & plexiglass made it less desirable and much more costly.
I have copied and reproduced several large paintings (48"x72") which a client wanted matted, mounted & framed. At this size, the 48" dimension was the maximum width foam board is available at (without having to place a very expensive custom order). The result of these framed reproductions was very nice, and suited the boardroom in which they were hung. The framing job was 100% custom, though. None of the materials were "off the shelf".