The image on The Shroud of Turin consists of linen fibrils colored apparently by substances produced through a cellulose oxidation-dehydration process. It has many of the properties of a light scorch. No evidence was found to suggest that pigmented or dye material were applied to the cloth by mechanical means. Iron oxide particles of sub-micron size are present on the surface of the cloth as are calcium and strontium. The blood areas give positive test results for proteinaceous material and appear to contain blood. The blood regions show the largest concentration of iron.