I have a customer who builds and sells commercial property (mainly dorms/apartments. They currently have a building under construction and they asked for four "poster boards" (36" x 72"). From what they said, two will be hung inside the windows and two will be mounted outside on the plywood that is cover part of the exterior of the building. I know I probably sound stupid, but by poster board does he mean PVC foam board? Hope all of the makes sense, any suggestions are much appreciated!