ring binders are often equipped with sheet lifters or other features to reduce wear and damage to their paper contents. Ring binders are sometimes banned from use for written journals, logs, or registers, which may even have pre-numbered permanently bound pages to discourage removal of pages, or at least allow a removal to be detected. Loose leaves in countries that use Letter-sized papers In U.S. and Canada, Letter-sized papers (8.5 x 11 inch) are used, and paper sizes are based on inches. The loose leaves in these countries have three punched holes on the left side of a paper, and the distance between two adjacent holes are set. The loose leaves may be exactly Letter-sized or smaller. Five Star sells Letter-sized loose leaves; Oxford and Mead sell 8 x 10.5 inch loose leaves. In libraries and print shops, hole punchers are regularly provided for punching 3 holes. Some bound notebooks have perforated lines for tearing off pages, and all pages have pre-punched holes, so that when torn off, they can be organized into a binder directly. Loose leaves in countries that use ISO paper standards In countries that use ISO paper standards (ISO 216), loose leaves of many different sizes are sold on the market. Design See: Hole punch ISO loose leaf typically has these number of holes: Width of ruled lines The most common widths of ruled lines are 6mm, 7mm and 8mm. Some manufacturers sell 9mm and 10mm ruled paper as well, to accommodate special needs related to writing CJK characters, which takes up more space than alphabet-based scripts. Accessories Many accessories are on the market, including punched zipper storage bag, punched "today"-ruler, card organizer, etc. Different countries/regions ISO-sized loose leaves are most often designed and manufactured in Japan, mainland China and Taiwan. Japan Japan is a major contributor to the market of ISO-sized loose leaves. In Japan, sizes of loose leaves such as A4, B5, A5, A6, A7 and special sizes such as "bible size / diary size" (e.g. by Raymay DaVinci) and are sold. Notable Japanese manufacturers include Kokuyo Co., Ltd. () and Maruman Co. Ltd. (). Kokuyo's products sell internationally and are available in the Chinese, European and North American markets as well. MUJI (無印良品, see ) has retail stores worldwide, selling products including ISO loose leaf paper, even in North America where ISO sizes are not used. Both Kokuyo and Maruman manufacture pre-printed calendar