What is the nature of the cloth?
The Shroud is about fourteen feet long and three and a half feet wide. It is four times as long as it is wide. The historian Ian Wilson and others have described it as being eight Talmudic cubits by two cubits.
As a burial cloth it is long enough on which to lay the body of a man on his back with his feet at one end and his head near the middle. The cloth is long enough to bring it across the front of body and back down to his feet. Its width is enough to cover him completely if his arms are not extended. See: Painting of the Holy Shroud by Giovanni Battista della Rovere.
The cloth is linen. Linen yarn, used to weave the cloth, is made from flax fibers. There are approximately 70 to 120 fibers in the yarn used for the Shroud. Each fiber is about 15 microns in thickness.
The weave pattern is three-hop (or three-over-one) herringbone twill. It is very distinctive, rare and would have been more expensive than plain weave or simple hop twill. In hop twill the weft or cross thread passes over two, three or four warp threads, under one, over the same number as before, and so forth for each run of a weft thread across the loom. The next weft is offset by one, and the next one, and the next one. That is twill.
Herringbone simply means the offset (twilling) is periodically reversed, hence the diagonal wale is reversed. The resulting appearance is that of a herring fish bone. Other decorative and complex patterns including lozenges, waves and zigzags can be created in twill weaving by varying the hop in different ways. You can clearly see the twill pattern in the fourth, fifth and sixth threads from the top.
Ray Rogers, a chemist from the Los Alamos National Laboratory has discovered a thin carbohydrate coating on the outermost fibers of the yarn. He believes the coating is an impurity layer (or residue) of starch fractions and saccharides from the natural soap Saponaria officinalis obtained from the Soapwort plant and that this coating resulted from an evaporation concentration during drying of cloth following washing before it was used as a burial shroud.
The cloth has a series of vertical or horizontal bands of darker and lighter tone that gives it a variegated appearance. These variegations are commonly referred to as banding and they affect the appearance of the image.