Fiber Reference Image Library

The Fiber Reference Image Library (FRIL) is a database of images of textile fibers acquired through the use of multiple microscopic techniques, and was initially created with support from the National Center for Preservation Training and Technology (NCPTT). FRIL contains comparative images of textile fibers examined using brightfield, darkfield, polarized light, and differential interference contrast techniques; each sequence of these images provides complementary information contributing to identification and characterization. Associated text provides description of details in the images and concerning the textile source of the fiber. The site is organized into collections of Plant, Animal, and Manufactured fibers. 
The initial collection includes images of fibers from 18th through 21st century garments from Ohio State University’s Historic Costume & Textiles Collection. The materials used to obtain these fibers are now housed in the Canter for Heritage Analytical Reference Materials (CHARM) at the Library of Congress (LOC).
Additional images of plant fibers are from the Woodlands Bast Fiber Reference Collection as the National Museum of the American Indian (NMAI) Pre-Columbian clothing, baskets, pouches, cords, and mats were often made from the inner layers of bark and plants. In the northern and eastern regions of North America, the most commonly used fibers were basswood, elm, nettles, dogbane and milkweed. A table containing a comparison of the fiber cross-sections can be found here. 
= FRIL Collections =
* Animal
* Manufactured 
* Plant
* FRIL (complete list)
= How to use the Fiber Reference Image Library =
Each individual fiber sample was micrographed using multiple techniques of microscopy: brightfield, darkfield, polarized light with the fiber at the position of maximum brightness, differential interference contrast, polarized light with the fiber at the position of extinction, and the latter with the addition of the first order Red plate. Additional pictures were taken of fiber groups, and features of special interest.
For the bast fibers, effort was made to isolate a single fiber, to discern distinguishing characteristics. The addition of the First Order Red plate to a fiber sample under crossed polars provides evidence of fibril spiral direction, i.e. S or Z, (the Herzog test). In addition, images were taken of fiber bundles and associated materials, thereby displaying the structures that remain adjacent to the fibers and that might provide additional identifying information. 
When examining manufactured fibers, the fiber is oriented at the position of maximum brightness under crossed polars and the First Order Red Plate is added to determine the sign of elongation. 
Thus fiber images of a single sample can be seen in a series within its collection, followed by images of additional key features representative of the fibers and the associated materials observed. The sets of images reveal features not visible with the use of one technique alone. Outstanding features of each fiber sample are noted on the page with each image.
For definitions of the morphological characteristics of the fibers, go to the page Fiber Morphology Definitions used in the Fiber Reference Image Library
For resources on microscopy go to the page Basics of Fiber Microscopy
FRIL was developed by: Kathryn Jakes, Professor emeritus, Ohio State University