These sturdy (60 pt.) archival fiberboards were developed specifically for the long-term storage and conservation of photographic materials. They are made of materials that are acid-free and contain no products (like lignin, ground wood, sulphur or recycled chipboard) that might harm negatives or photographs. Plus a unique patented Dual Chemistry Alkaline buffered exterior and a neutral non-buffered interior, separated with a polyester barrier. These boxes will give your photographic collection the best possible protection. All of the boxes come with metal reinforced corners. Drop front storage boxes are available in a wide range of sizes. The drop front on one long side of the bottom piece allows collections to slide gently in and out of the box, as fingers do not force their way down the sides with this style of box