Joseph Kohlbeck

Particles in many colors were observed on untreated fibers from the “blood” areas of the shroud. Magnified 625 times, this fiber displays a range of colored particles from black to colorless, with red predominating. The authors propose that all the particles may originally have been red and that they underwent a slow natural change over time, similar to the accelerated change induced by Cargille oil, as shown in the photograph.