More than 600 years ago a 14-foot length of linen suddenly appeared in the pages of history. Showing full-size back and front images of a crucified man, it was exhibited, and accepted by the general public, as the Shroud of Christ. Some, however, have doubted its authenticity up to the present. In 1978, sticky tapes applied to the Shroud surface removed many fibers from image areas which have been shown by microanalysis to be coated with a watercolor paint. The pigments have been identified by polarized light microscopy as red ocher and vermilion; the medium as a collagen tempera. The author feels that these findings, confirmed by electron microprobe analyses, prove that the Shroud is a painting.