Pinit Conservation-Grade Backings for Window Cards Posters. 14-1/4 x 22-1/2". .040" thick Alpha Cellulose board. Acid-free, Lignin-free, Buffered. All white. Indefinite Storage. SKU: KAF401422 (0)No Reviews yet Add to Shopping Cart Details Conservation Grade Backing Board for Window Card Posters. 14-1/4 x 22-1/2" .040" thick. All white. Lignin-free. Acid-free. Buffered. Contaminant-free.... Details Back DetailsConservation Grade Backing Board for Window Card Posters. 14-1/4 x 22-1/2" .040" thick. All white. Lignin-free. Acid-free. Buffered. Contaminant-free. Meets the Library of Congress archival standards. Indefinite Storage. Reviews 0 Back Ratings & ReviewsNo reviews availableBe the first to Write a Review