I'm a Shroud of Turin expert, sort of second tier I suppose since I restrict my work to processing the images and giving talks on the shroud. This is worth a look for those who wonder how the image got on the cloth.
This video explores some claims about the shroud and some work to try to understand it. On the whole it shows how difficult it is to get any result that is convincing. People think they see words. The three image production efforts are: 1) bas-relief transfer with pigment, 2) hypothetical ancient photography, 3) maillard reaction between ancient cloth with starch fractions and preliminary bodily decomposition gases.
The test was to look at the microscopic state of the fibers and at this level the maillard reaction was most convincing. Neither of the images was anywhere near as subtle or convincing as the actual shroud but the photographic attempt came closest. The idea of words on the shroud forming a first century death certificate, well ... I think that's extraordinarily unlikely.