binder

n. a device used to hold loose documents together; a notebook a fastener used to hold loose sheets together a bookbinder a substance used to hold disparate components together in a solid or to give even consistency to a liquid

Notes

Examples of binder4 include gelatin or collodion used to bind the metallic silver that forms a photographic image to the base, or the substance that holds the magnetized metal particles in an audio tape to a base.