Loose leaf
Loose leaf paper may be sold as free sheets, or made up into notepads, where perforations or glue allow them to be removed easily.
US companies such as Staples and Office Depot manufacture and sell letter-size loose leaf products in their retail stores.
When it comes to ISO-sized loose leaf systems, since Japanese companies (e.g. Kokuyo, Maruman, MUJI, King Jim) are major designers and manufacturers of ISO-size loose leaf systems, whose products are sold internationally, corresponding Japanese terms will be included in parentheses throughout this article.
These hole punches are sold by the companies alongside their loose leaf binder or paper products, and usually there are third-party components for sale as well.
JL Darling produces waterproof Rite in the Rain loose-leaf paper for outdoor (e.g. field) purposes.
This ability to rearrange and update the contents of binders is convenient for students and others, who can carry only the papers they are likely to need on a given day, while leaving the remainder elsewhere.
The ability to add or remove an arbitrary number of pages has been useful for reference works that are frequently updated, such as computer software manuals, parts catalogs, and legal indexes.
The chief disadvantage of loose-leaf paper is that individual pages can be easily removed or lost from its storage binder due to tearing or wear of the punched holes.
Besides that, loose-leaf system may take up more space and be heavier compared to common glued or threadbound notebooks, due to the hinge (typically metal) involved.
Staples and Office Depot produced "discbound" loose leaf systems: ARC and TUL, respectively, and sell them both in stores and online.
Japan is a major designer and manufacturer of ISO-sized loose leaf systems, and their products are widely sold in east Asia, Europe and North America, especially through online resellers.
Notable companies include Kokuyo, Maruman, MUJI, King Jim and Lihit Lab.
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.
MUJI (無印良品, see 良品計画 [ja]) has retail stores worldwide, selling products including ISO-sized loose leaf paper, even in North America where ISO sizes are not commonly used.
Lihit Lab (リヒトラブ) produces a special type of loose leaf, with rectangular holes (instead of round ones) with non-standard spacings.
