A long strip of copper is cut to size. Due to the small size of the copper tube, it can only be cut by hand using a small steel plate. After cutting, the inner and outer edges of the copper tube become very sharp. It takes a lot of time to file the inner and outer edges to remove the sharp edges of each copper tube! The surface of the copper tubing is hand colored and sanded again! Giving the copper pipe both the aged part of summer and the shiny part of hand-polished copper. Realizing the handmade nostalgia may seem simple, but it's not! Play the role of calligraphy and painting. Product Features Cover material: imported crazy horse cowhide Product Size: Portable model length and width of about 19 * 11CM, standard model length and width of about 22.5 * 11CM, thickness of about 3CM Inside page size: portable models about 16.5 * 9.5CM, standard models about 21 * 11CM Packing weight: portable models about 0.6KG, standard models about 0.8KG Paper quality: 100G kraft paper / Dowling paper, (the market ordinary printing paper 70G) Pages: about 36 pages per small core, about 72 pages per small core, about 108 pages per book, about 216 items per book.