A loose-leaf book is one of the most commonly used stationery in daily work and study, consisting of covers, binders (or coils), and paper. The biggest difference from ordinary notepads is that the loose-leaf book is more flexible to use, the paper can be disassembled, replaced, combined at will, and easy to organize, and users can also DIY according to their own preferences. The loose-leaf book can be used for writing notes, notes, and drafting, etc.