“Leonardo” 4 D-ringbinder boxes are made from Duralong Wave archival micro corrugated board, ideal to take album pages with multihole binding edge in polyester, polypropylene and glassine. Extremely strong and rigid with double thickness walls on all sides of the base and the lid and a double layer of board on the base. They are fitted with a practical herringbone cotton tying tape. On request it is possible to customize the boxes covering them with cloth of various colours.