Over the years, a bit of incorrect information about the scourge marks we see on the shroud has been promulgated, which has led to misunderstandings. Watch this clip from the 1977 documentary, “The Silent Witness.” During a discussion of the scourge marks, beginning at about the two minute mark, while showing a Roman flagrum, you will hear Monsignor Giulio Ricci say, "the proportions and measurements are identical."
Is this because the flagrum in question was, in fact, created to the shroud’s measurements? Or, if not, is it a perfect fit for what is undoubtedly a non-standard, handmade whip from antiquity?
Across the vastness of the Roman Empire, among its own soldiers and the many mercenaries employed by the Romans, there were countless varieties of scourging whips. Some undoubtedly had three leather thongs like the one in the film. Some had more. Some probably used hemp rope instead of leather. Some were perhaps tipped with handmade metal dumbbells made of copper, iron or lead. Perhaps the dumbbells were sand cast or pounded into shape at a forge or hammered out from metal rods. Perhaps some scourges were tipped with washer-like disks, metal beads or bits of bone. There certainly was no standard size or type. It would be extraordinary to find one whip in which, "the proportions and measurements are identical."
It is probably worse than that. Some believe, after reviewing the evidence, that the scourging whip in the film was created to the shroud’s measurements? I doubt there was any intent to deceive. Fr. Ricci himself says the flagrum is a reconstruction.
That said, it is still reasonable to infer that the many pairs of marks, seemingly contusions, that appear where they do at the angles that they do on the back, front and legs of the man on the shroud, are whip marks made with a flagrum probably tipped with dumbbells or something similar. Everything else that Fr. Ricci says seems plausible.