Do not wrap ceramics, wood, marble, or other porous materials in old newspapers. The ink used to print will eventually stain the pieces. Newsprint is high-acid paper and it can discolor other materials, especially other pieces of paper, over time. Recycled paper is usually bad, but some photocopy paper is acid-free and good for archival storage. Watch out for cardboard boxes and plastic boxes. Many folders, scrapbooks, and plastic sleeves can damage old paper items like autographs, photographs, or cards.