The ideal electronic book includes characteristics of prints and displays; the legibility and portability of print with the variability and dynamics of electronic displays. An interesting question is to ask whether the fundamental technology will come from the display world (SID) or the image world (IS&T). The first-out-of-the-block candidates come from the display world, particularly liquid crystal technologies. The main effort has been to make LCD displays as thin, light, durable, and low power as possible.Consider the problem from another direction. Print technologies are wonderfully legible, light, durable, and low power, but what can be done to make the content variable? A number of ideas have been proposed. For instance, consider the possibility of moving a xerographic image in and out of view: say with rotating or electrophoretic toner particles! Consider the possibility of electrochromic technologies where the “printed image” is switchable by oxidation or reduction of dyes.This talk describes the work at E Ink Corporation where materials similar to xerographic liquid toners and electrophoretic displays are combined with polymeric encapsulation to give devices with the optical qualities of prints as well as the addressability of electronic displays. The excellent optical properties arise from the scattering and absorptive properties of pigments and the variable content arises from the ability to move the pigments into and out of view.