Part 1 of an article by Edward R. Schwarz on using the microscope to study wool fibers and wool fabrics. It argues that attempts at artificial wool fail to account for the fiber's complex structure, and that manufacturers, like wool growers, should test fibers. It describes the cuticle, scales, cortex and medulla, then reviews research on fineness, spinning quality, crimp, grading, felting and chlorination. Two photomicrograph figures compare imitation and real wool fibers, and a numbered reference list closes the piece.