Pinit Archival Foam Board Backings for 12 x 18" images. .1875" thick (3/16"). All white. Acid & lignin-free. Buffered. Indefinite Storage. SKU: KFB1218W316 (0)No Reviews yet Add to Shopping Cart Details 12 x 18" White Foam Board. 3/16" thick. Lignin-free, acid-free, buffered. Museum Grade Archival. Details Back Details12 x 18" White Foam Board. 3/16" thick. Lignin-free, acid-free, buffered.Museum Grade Archival. Reviews 0 Back Ratings & ReviewsNo reviews availableBe the first to Write a Review