Blood serum retraction rings

Another evidence the blood stains is real blood are the blood serum retraction rings.

Serum is the component of blood that does not result in clotting.

Blood is primarily composed of RBC (red blood cells), WBC (white blood cells), plasma, and serum. Plasma and serum are the main components of blood and are routinely used in blood group test experiments for determining the patient’s blood group.

Plasma and serum can be separated by centrifugation of blood on the basis of weight, size, and density. The serum is the liquid obtained after blood is allowed to clot, whereas plasma is obtained after treating blood with anticoagulation compounds.

The serum is the liquid or undiluted part of the blood, which lacks clotting factors. Hence, it is formed after blood coagulation.

https://byjus.com/biology/difference-be … and-serum/

Surrounding the blood stains on the TS are serum marks (serum retraction rings, serum halos), which are visible under UV light.

One of the most interesting characteristics of the bloodstains on the Shroud is the presence of
serum “halos/rings” surrounding various wounds in the ventral and dorsal portions of the image.
These areas were noted in the 1978 STURP investigation during examination of the cloth under
ultraviolet light.

https://www.shroud.com/pdfs/anc-kearse-pap3.pdf

Everybody can see the fluorescent halo around the main bloodstains in the UV-Vis
photographs. In fact, small fluorescent haloes were also observed around all the blood marks,
even around the scourges.
This simple observation is and remains probably the most definite proof that the blood is real
blood.
There is no way to observe such a spontaneous behaviour for a painting. Therefore, to obtain
these fluorescent haloes, the artist would have to spend hundred hours to deliberately paint
them with collagen (which, incidentally, would be not fluorescent in body-image areas) … so
that they would be invisible with the naked eyes.

https://www.shroud.com/pdfs/thibault%20final%2001.pdf

Also the border of every blood mark
shows the typical yellowish fluorescence of the serum exudate ring around scabs as expected
for clot retraction transfer marks, thus confirming the medical forensic analysis and the
observations of Barbet (cf., Figure 2). Further, all the scourge marks now show a pattern of
scratches on the narrow ends, not visible in reflectance, that would be expected for wounds
produced by a typical Roman scourge. Therefore an artist painting the blood marks would not
only require a 20th century knowledge of the physiology of clot retraction, but would have to
produce images of serum rings and scratches that are only obviously evident under ultraviolet
excitation.

https://www.shroud.com/pdfs/ssi43part1.pdf

Each individual blood wound
shows a distinct serum clot retraction
ring; such blood halos are only visible
under ultraviolet light (5), a detail that a
forger is unlikely to have been familiar
with.

https://www.shroud.com/pdfs/kearse.pdf

One would need a constant supply of fresh clot exudates from a
traumatically wounded human to paint in all the forensically correct images in the proper non-
stereo register and then finally paint a serum contraction ring about every wound. Logic suggests
that this is not something a forger or artisan before the present century would not only know how
to do, but even know that it was required.

https://www.shroud.com/pdfs/adler.pdf

It would make no sense to have serum retraction rings if the TS was the work of an artist by either paint or blood. Nobody at that time understood the chemical makeup of blood and the properties of serum. Even if an artist did understand it, why and how would he be able to paint it? If he used blood, how was he able to apply it to the cloth to be microscopically and UV realistic? Why would he even go to so much trouble if nobody until hundreds of years later would discover such details?

The most logical explanation is the blood marks are the result of an actual scourged and crucified body.