Pinit POLYESTER (Mylar) Sleeve 15-1/2 x 18-1/2". 4 mil. NO flap. Indefinite Storage. SKU: S1518R (0)No Reviews yet Add to Shopping Cart Details Polyester (Mylar) Sleeve for 15 x 18" formats 15-1/2 x 18-1/2" 4 mil. NO flap. Details Back DetailsPolyester (Mylar) Sleeve for 15 x 18" formats 15-1/2 x 18-1/2"4 mil. NO flap. Use for Art, Prints, Posters Reviews 0 Back Ratings & ReviewsNo reviews availableBe the first to Write a Review