Check out any of the large home supply stores for the Coroplast. Rona sells it here in both half sheets, and 4'x8' sheets - and they come in a few colours. Look for them in the area where plexiglass is sold. They're easy to cut with an old seam ripper- just put the prong part in the hollow corrugated part and zip up the entire length of the sheet. Fold it in half and zip up the other side of that hollow tube. They you only have to cut across the grain in short lengths.