“Della Robbia” folder boxes are made from Duralong Basic economic conservation board, ideal for vertical storage of loose documents or documents put inside folders and envelopes.They are designed to protect artefacts from dust and light, and open like a book to allow easy moving of the contents; the outer flap and the inner tabs have a clam self-locking closure. Simple and quick to assembly, they have a hole on the spine that facilitates the grip and the handling of the folder on the shelf.