"Electronic ink" refers to a type of technology that imitates the appearance of traditional ink on paper. It is used to display information on electronic screens, like e-readers, and allows for easy reading even in bright light. Full definition
This was the first recorded application of electronic ink to newspaper publishing. (en.wikipedia.org)
All use high - contrast electronic ink screens that only use power when «turning» the page, so the batteries last for weeks or months at a time. (gigaom.com)
In fact, paper currencies and instruments (or electronic ink on paper) probably have more «believers» than all of the religions in the world combined. (investmentresearchdynamics.com)