Although "flat wrap" is a common industry term, we prefer "deflated wrap."
Or the German: "Deflaturwrap."

Along a Long Road (Sheet) Price: $ 4.25 Item Code: FWLI0009 From Frank Viva’s first children’s picture book – to be published in June 2011. Quantity: 1 flat sheet Size: 20" X 30" Printing: Litho on uncoated, 100% post-consumer waste paper Packaging: Shipped flat QTY: