This EVA foam has a shore hardness of 38.  It comes in sheets that are 600 mm x 600 mm (approximately 24″ x 24″) squares.  Each sheet is coated with an industrial adhesive.  Simply peel the backing and stick to another piece of foam.  After 24 hours of curing time, you will have a very strong bond.  This allows you to apply details without having to use additional contact cement.