It’s likely you’re correct, I’m working from a failing memory here. . . and been working hard packing to move to St. George, Utah in just over a month. We’re getting hell out of HELL, California’s suburb of Hell, that is.
The image lies on the top one-thousandth of an inch of the linen fibrils - same as the depth of a bacterium. By the way, can’t be a scorch, either. Even a light scorch would go all the way through the fibrils.