Use 1/2" (1.27 cm)Foam Sheets for layout and diorama bases, as well as to form tunnel walls, ceilings or overpass supports. Pin with Foam Nails and glue in place with Foam Tack Glue™ or the Low Temp Foam Glue Gun and Glue Sticks. Each Foam Sheet measures 12"w x 24"l (30.4 cm x 60.9 cm) 1 sheet/pkg