“E Ink” is a company that makes Electronic Paper.
They use charged ink particles floating in a fluid to create images. Apply a charge across the fluid and the ink moves to the top or bottom based on its charge. This is why they don’t require energy to sustain the image they represent, they only require energy to change images.
E Ink is like a magnidoodle.
They don’t emit their own light, but this is a benefit and a drawback. It’s a neat spot that opens up the Tradespace for screens.