Shroud of Turin

[okasha]

36. Belief in what, ed?

One doesn't "believe" in the properties of art materials--those are physically and chemically established. In the case of tempera, they've been established for a couple thousand years. The primary fact about tempera that has a bearing here is that it cannot be painted onto a non-rigid support, such as linen or other canvas. In the absence of a rigid support, such as wood panel, the paint would simply craze (crack) and fall off. That's because the paint film formed by tempera is rigid. If the shroud were a tempera painting, the image would have been destroyed long ago by the handling, folding, unfolding, patching, sewing to backing cloth, heating and water drenching to which we know that it has been subjected. There's also no evidence that anyone has offered that the cloth was ever gessoed. Oil, tempera, acrylic and watercolor all require a coat of gesso on the support, whether the support is flexible (canvas for oil, acrylic and watercolor) or rigid (usually wood panel, which can be used with any of the four.) The exception is artist-grade watercolor paper, which doesn't require gesso because it is usually sized during manufacture. The shroud is not made of watercolor paper, even though the Fabriano mill in Italy has been making artist's paper since 1282 and later supplied custom paper to the likes of da Vinci and Michelangelo. It's damn good paper; I use it myself.

Which brings me to this: Modesty forbids me to call myself an "art expert." I am, however, a working professional artist, mainly in photography and watercolor. I have a good many art history hours under my belt, as well as a lot of independent study. There is nothing in this post that you can't fact check for yourself if you feel compelled to question it, and none of it that is disputed.

It's all mere materialistic facts, dontchaknow.