Yep, good point on the highlighter! I forgot that one. When you overlap grays and layers of highlighter (as it gets darker with each layer... maybe in 1/8ths?

Yep, good point on the highlighter! I forgot that one. When you overlap grays and layers of highlighter (as it gets darker with each layer... maybe in 1/8ths?), I suspect it's just doing a gray/black checkerboard - I can't tell for sure with one or two layers of highlighter, but it's pretty clear to me on the third layer that there are gray pixels between the black pixels. And yeah, the highlighter's ghosting can get pretty extreme :) Since it clears up with a back/forward page turn I think it's a reasonable tradeoff... but it does serve as an interactive example of how much eink struggles with gray<->grey transition accuracy, which is why anti-aliased text is so much of a problem after a couple pages on literally every device.