Pinit Conservation-Grade Backings 28-1/4 x 19-¼" .040" thick Alpha Cellulose board. Acid-free, Lignin-free, Buffered. All white. Indefinite Storage. SKU: KAF402819 (0)No Reviews yet Add to Shopping Cart Details Conservation Grade Backing Boards for Maps, Newspapers. 28-1/4 x 19-1/4" .040" thick. All white. Lignin-free. Acid-free. Buffered. Contaminant-free.... Details Back DetailsConservation Grade Backing Boards forMaps, Newspapers. 28-1/4 x 19-1/4" .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