The paper is almost the same weight as the XPS foam. The paper, on both sides, is what gives the strength to the board. Strength is achieved due to the foam sandwich construction, paper acting as a stressed skin. The paper can be peeled off easily. This can be used to lighten the structure, but also reduces the strength. Also without paper on one side the sheets can have a tendency to warp. Although the Foam is not CA safe, the paper is. CA is much, much lighter than Hot glue. Lighter models fly better, always. Recommend to use CA judiciously where possible, where the foam edges do not come in contact with the adhesive. Foam board is lightweight but strong, and can be cut into any shape with clean edges, 3/16Inch thick foam corn board ideal for school project, signboards, picture framing and mounting, 15 pack polystyrene foam sheets black Foamcore Board Features: Made of Acid free materials, easily to cut into shape and resists warping Lightweight yet study black foam board sheet, ideal for posters or presentations Features smooth and rigid surface, works well with pin, markers, paints, adhesives, and fabrics Three layers foam core mat, the polystyrene core covered matte Plastic on both side Multi-function backing boards, good for artwork, school project, picture framing, mounting displays and sign boards Technical Specifications - Material - XPS foam core laminated with Bright White Medium-Glossy paper on both sides Thickness - 3MM Density : 400 GSM Colour - Black Sheet Size - 12 inch x 8.5 inch Quantity - 6 Sheets per box. Weight - 375 gms