I've invested several hours this weekend drymounting three 11x14 prints into a three-print panorama. I'm mounting all three prints on one mat board which measures 40x20 inches. Getting all the prints cut square accurately match-trimmed and mounted straightly is quite the challenge. Its fairly easy to do with 8x10 prints and smaller but as print size goes up, the "challenging" level goes up exponentially I have found. Right now my method is summarized as dry mounting three 11x14 prints on a single 40x20 inch mat board, then overmatting with another single-window piece, all with 4-ply mat board. Looking for a possible better way, including framing ideas.