A small portable UV/vis spectrophotometer is constructed from readily available components (a continuously variable filter wheel, LCD display, silicon photodiode, LF355 op amp and 9 volt battery) with a resolution of 17nm. This device was used to obtain reflectance curves from the various areas of the Shroud. These curves were compared to others measured with the use of a Cary 14 upon fabric, pigment and blood simulations of similar type in the laboratory. The body image is the result of degradation of the cellulose itself rather than any foreign substance; the blood marks are human blood; and the presence of Fe₂O₃ could not be confirmed by the tests. See 17-1288, 18-3, 18-10, and 18-38. -- AATA