I've strip-pieced most of the black strata needed, and stuck them up on the design wall, pinning the other tiers in place so I could get a glimpse of the whole. The little tags on the turquoise are marking spots I was planning on altering. But now I see a larger problem. The turquoise tier has a much wider range of value than any of the others, and I don't think that works. I think I'll need to revise more deeply, taking out/covering up the dark teals. Of course I could go the other direction--add more value range in the other tiers. But I think a smaller range is more in keeping with my vision of the piece--and adding a wider range for black isn't possible in any case.
I want to feel closer to the finish line with this piece. . . Instead of getting easier as I go, the challenges keep adding up. I have to keep the mantra of "persistence" in mind.