Pinit Archival Foam Board Backings for HALF SHEET POSTERS 22 x 28" images. .125" thick (1/8"). All white. Acid & lignin-free. Buffered. Indefinite Storage. SKU: KF2228125 (0)No Reviews yet Add to Shopping Cart Details Museum Grade 22 x 28" Half Sheet Poster Backings .125" thick, acid-free, lignin-free Buffered Foam Board. All white. Use for Indefinite display. Details Back DetailsMuseum Grade 22 x 28" Half Sheet Poster Backings.125" thick, acid-free, lignin-free Buffered Foam Board.All white. Use for Indefinite display. Reviews 0 Back Ratings & ReviewsNo reviews availableBe the first to Write a Review