Thanks very much for responding. You mentioned backlight, and forgive my ignorance, but is this type of E-paper not front-lit?

It’s not actually normal e-ink, it’s a kind of LCD, that’s why they say e-paper and not e-ink

I think it’s like the kind of LCD you see on calculators and clocks and the original Game Boy, that doesn’t need a backlight to be visible but can have one