New ePaper doubles color definition for clearer e-reading

Reading in color on an e-reader can be like reading a washed-out photocopy of a magazine. It means putting up with faded comics, grainy photos and text so murky that you feel you are deep underwater. E Ink says its new Kaleido 4 is built to tackle all that. But is this the upgrade that finally makes color ePaper feel like the real thing?

Kaleido 4 is the latest generation of the color ePaper platform used in e-readers and tablets from Kobo, PocketBook and Boox, with Amazon's Kindle Colorsoft using a customized version. Compared to its predecessor, Kaleido 3, E Ink claims the new panels double the color gamut volume (a measure of the range of colors a screen can show) to "more than 40K," reflect 15% more white light, deliver 50% more contrast and play video at up to 18 frames per second.

To understand why all those figures matter, it helps to know how the technology works. Kaleido doesn't use colored ink at all. Instead, it lays a color filter over a standard ePaper panel that only shuffles black and white pigments – think of a sheet of stained glass placed over a printed page. But it's not perfect. Kaleido 3 shows black-and-white text at 300 pixels per inch (ppi) but color at just 150 ppi, with a palette of 4,096 colors. The filter also makes the page look like a poster left too long in the sun, washing it out and reducing contrast compared to monochrome e-readers.

Brighter whites and higher contrast cut through that murkiness, and E Ink says the changes also reduce the perception of graininess. A new oxide thin-film transistor backplane – the layer of tiny transistors that switches each pixel on and off – supports higher driving voltages and faster refreshes.

Kaleido isn't E Ink's only color option. Its Gallery 3 technology uses colored pigments that move to form the image. E Ink lists the platform at 300 ppi, although the reMarkable Paper Pro, which uses it, runs at 229 ppi. The problem is the speed. According to E Ink, a black-and-white update takes 350 milliseconds, but color takes 500 ms in its fast mode and 1,500 ms for the best quality.

So has Kaleido 4 closed the gap? We don’t know yet, and the launch leaves two big questions open. E Ink hasn't published a color resolution or a palette size for Kaleido 4, either in its announcement or on its website. Good e-Reader reports that E Ink's color now reaches 300 ppi, double Kaleido 3's 150 ppi, which would be a major leap. And we don't know if the new technology will have more actual colors in its palette, or what exactly E Ink means by its "40K" figure.

The first device to use the new screens will be Hanvon Technology's M10C II, a note-taking tablet aimed at the Chinese market. Combining Hanvon's own refresh technology with the T2000 timing controller developed by E Ink and Himax, E Ink says the tablet turns pages and scrolls 27% faster. A redesigned front light also promises more natural color.

Amazon and Kobo haven't announced Kaleido 4 devices yet, though Good e-Reader expects new models from Kobo, Nook, Boox and Bigme in early 2027. When they arrive, a full spec sheet and some hands-on time will tell us whether Kaleido 4 looks as good on the e-page as it does on paper.

Source: E Ink