Archival Methods Print Lux Box 16.25 x 20.25 x 1-1/8", Black Box core is Kappa binder's board (.090), a bookmaking board with no glue between layers. Lined with 80 lb. acid- and lignin-free black paper; PAT tested and passed Covered in black bookbinding paper with a moisture-resistant, 100% aqueous acrylic coating. Adhesive is pH balanced and buffered, &lt;.0008% sulfur content. Close-tolerance construction to keep out dust.