Electronic paper shows an image by arranging tiny particles and then holds it with almost no power, which is why e-readers last weeks on a charge and are easy on the eyes. This technology is spreading to computer monitors, note tablets, shelf labels and signs.
For reading, writing and displaying information that changes rarely, these screens are comfortable and extremely efficient, and they stay readable in bright sunlight. They refresh slowly and most show limited colour, so they are unsuited to video or fast interaction, but for the right tasks they offer a calm, battery-friendly alternative to glowing screens.