Make them with 13 oz - they will be fine.
I was thinking the indoor lighting wouldn't cause much of a shadow on the other side.
For what it's worth, Fellers' 16oz KOMA material (double-sided & blockout) seems to be very resistant to edge curl even though it's not marketed that way. I use it for most everyday type banners mostly because of that.
insignia said:We've seen a ton of failures using KOMA, everything from serious cracking/delaminating to ink not adhering properly. It seemed like a good budget double-sided 16oz material but it doesn't hold a candle to a good 18oz blockout IMO.