These are the .060 White Styrene Super Sheets from Midwest Products.

FEATURES: Solid white in color
          Flexible...bends and forms easily
          Compatible with many plastic adhesives
          Compatible with most paints, including Testors, Humbrol Enamel,
            Floquil Model Railroad Paint (solvent based)
          Thousands of uses including architectural models, school projects,
            fine arts, hobbies, do-it-yourself projects, and more

INCLUDES: Four sheets

SPECS:    Thickness: .060"  (1.50mm)
          Size: 7.6" x 11" (194mm x 279mm)

COMMENTS: Some acrylic paints will rub off, so test before using them on your
            project.

                                                                     tlw 2/6/08
                                                                         ir/jxs