You have no idea. Check out the history of testing carried out on the shroud. It's a cesspool.
"The microscopist Walter McCrone found, based on his examination of samples taken in 1978 from the surface of the shroud using adhesive tape, that the image on the shroud had been painted with a dilute solution of red ochre pigment in a gelatin medium.
McCrone found that the apparent bloodstains were painted with vermilion pigment, also in a gelatin medium.[5] McCrone's findings were disputed by other researchers and the nature of the image on the shroud continues to be debated.[4]: 364–366" - Wiki
