I was looking at "poster hangers" rather than frames -- just a pair of 27" wide rods that clip on at top and bottom. The top rod lets you hang from one or more nails while the bottom rod is weighted to hold the poster flat. Should be a better absorber than the wall if anything.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8