Talking bus-shelters, or never folded stuff. I just use bruce's kong tubes, or original 4"x4"x6' shipping boxes and store as many rolled inside each other as I can get in there. If you have a full tube or a box, stuff doesnt flatten (unless you pile boxes) and ends do not crush regardless of being horizontal or vertical.
The cardboard paranoia, we will all be dead before the card board would effect anything printed the last 40 years. Cool, dark, relative humidity 45% range, good to go.