Person

STURP

The Shroud of Turin Research Project (STURP) was a U.S.-led multidisciplinary team of scientists who conducted the first comprehensive direct-examination study of the Shroud of Turin in 1978, granted five days of hands-on access by the cloth's custodians. Its roughly forty members spanned physics, chemistry, biology, forensic pathology, photography, and imaging, drawing several investigators from Los Alamos, Sandia, and Air Force laboratories.

Findings

STURP's published conclusions established the empirical baseline that subsequent Shroud research either builds on or attacks:

The image is not the product of paint, pigment, dye, or applied liquid, no brushstrokes, no medium pooling.
Image coloration is confined to the outermost 1-2 microns of the linen fibrils.
Bloodstains are real blood (subsequently typed AB human, with bilirubin) and were laid down on the cloth before the body image formed.
The image encodes spatial / depth information consistent with a draped 3D body (corroborating the Secondo Pia photographic-negative discovery and the 1976 NASA VP-8 analyzer result).

STURP did not arrive at a positive image-formation mechanism. Their final 1981 summary concluded that the image "remains a mystery", a phrase the apologetic literature leans on heavily.

Significance

STURP is the load-bearing citation for any "the Shroud is not a painting" argument. Critics of authenticity generally accept the no-pigment finding but contest the inference from "we don't know how it was made" to "it cannot have been made by any natural or artistic process." STURP itself was not part of the 1988 carbon-14 dating campaign and took no position on dating.