Okay, I haven't been working with it long enough to have extensive experience with how the Fabricator works, but this doesn't seem to be optimal.
It's one of the presets that came with either the original Fabricator, or maybe the Ye Olde Clothe, or Mach Pack collection. A nice black (well, charcoal) damask. Looks perfect in the work window.
But it renders with all of these pale spots and streaks. The lighting used isn't complex. It's Fisty's simple lighting that shipped with her collection of sparkle shaders. I've tried other lighting and got the same thing, except that the spots and streaks are in slightly different places.
I'm assuming that the problem is the specular so I've turned it way way down for the current attempt, and since it's taken 5 hours to get 20% done, I don't anticipate knowing whether that worked for some time yet.
But what is causing this? Does the shader require a skydome or something? None of the other Fabricator shaders that I've used have had this problem. This render was the worst with two different colors of spots, the really pale ones and the rather grey ones along the side of the ribcage. There is nothing like this in the scene, and I can't think of anything that would account for it.
(ETA: Red blotch is just to block oput something that isn't relevant to the issue.