I belong to a small guild and our quilt show is held both indoors and outdoors. Participants have the option of not hanging their quilts outside. We have never had any problems - however the weather has always been good. I personally believe there is something magical about seeing quilts hung outside with a nice breeze ruffling them and shade from trees protecting the work and fabric - however if I had personally spent countless hours piecing and quilting a masterpiece, I probably would prefer to have it shown inside. Just MHO.