Archival Methods Textile Storage Boxes, 30x18x6.25", Gray, Package of 5 Pulp: Purified alpha cellulose pulp, acid and lignin-free. pH: 9.0 (+-).5 buffered with calcium carbonate, 3% reserve. Single wall 1/8" thickness, B-flute 200-LB test. Color: gray, dyes are color-fast and non-bleeding. Adhesive: modified starch, min. pH 8.5