(The world should go green & natural.) Our storage box are made of paper material, which is friendly environment. Paper Material: 300G color printing papercard + strong E-flute + white bottom papercard. (The photos attached for your reference.) About "NingBo(China) Xinguang Culture Packing", a manufactory of : Paper Stationery(File Holder, Folder,Storage Box); Paper Packing(Bags,Boxes,blister card); Promotional Gift (Paper Writing Board,3D puzzle images, vivid doodle pad.).