The photo I linked to supposedly is how the tablet looks like in full sunlight, which I would assume would exhibit the best possible contrast. But the background is awfully dim (around #987 in the photo) (also in comparison to the white frame), and the text isn't very black (around #433). This looks like a contrast ratio of roughly 4:1. The photo probably isn't the best, e-ink displays usually have a contrast ratio of around 15:1. But that's still very low, printers can achieve a 100-200:1 contrast ratio for black ink on white paper.