A folder is a container stationery for categorization of documents such as files and printing papers. It can be bought in stationery shop. Usually, students and offices need to use folders. Ordinary folders are simply folded together for easy carrying, and some have two rings that require pinholes to be used. It is a tool used in the process of commercial or business activities to store, protect and regulate the management of paper documents. Now the document folder has been given the function of image display in business activities. It can be used to hold all kinds of paper documents, but not limited to this. Materials include PP, PVC, cardboard, and some are imitation leather, cloth and so on. What can be bought in the market is usually based on standard A4 files. There are many types of folders: single-strong folders, double-strong folders, reference books, two-inch folders, three-inch folders, different specifications of double-open folders, single-page folders (also known as L-type folders), multi-page folders.