This has been forming on my studio wall for a while now. It's currently a bit bigger than what's shown in this photo, but is ready for some sort of backing. Right now these half-circles from National Geographic magazines are mounted directly onto the wall. But for the purpose of installing it elsewhere, I have been looking for materials that I can use for mounting these papers (so that it can be installed in strips). My ideal material would be micro-thin (so that I can maintain the feel of the paper being mounted directly on the wall), white (to match most installation walls), and able to use adhesive mounting materials (and not have some of the surface removed by adhesive backings, as would happen with card stock or some other thick paper material).
I'd found some very thin birch plywood, but it did not come in any large sheets. I also looked at acrylic and plastic, but again, did not find it easily or cheaply in a larger sized sheet. However, I discovered a huge sheet of this stuff, "plas-tex," at Home Depot the other day and realized it might be the right thing. I can cut it, adhesive works on it, it's sturdy, cheap, and it's about a millimeter wide. Who knew this existed?