The Fiber Reference Image Library (FRIL), https://fril.osu.edu/, is a digital database that contains micrographic images of textile fibers examined using brightfield, darkfield, polarized light, and differential interference contrast techniques; each sequence of images provides complementary information contributing to identification and characterization. Associated text provides description of details in the images and information concerning the textile source of the fiber. The site is organized into collections of plant, animal, and manufactured fibers; commercial and noncommercial fibers are included and new collections are added regularly. Subcollections include images of fibers from 18th, 19th, and 20th century garments from Ohio State University’s Historic Costume & Textiles Collection. These subcollections are linked to a database of full and close-up views of the garments. FRIL supports the textile conservator in fiber identification and characterization of fiber condition. It also can be used in customs verification, in forensic investigation, and in fiber research as well as a teaching tool that engages young students in science, arts, and humanities through the subject of fashion, textiles, and fibers.