The expectations for electronic paper can be summarized as flexibility, readability, and multi-functionality. It focuses on the goal of readability. Paper-like readability should be accepted as the most important target of electronic paper. A concept of readable electronic paper is proposed, and its expected properties, style variations, applications, and various candidate technologies are summarized. As an indication of the realization of readability, an evaluation of user comfort when conducting reading tasks on paper and an LCD shows that free handling of the medium is an important factor in achieving excellent readability. The preferences for electronic paper can be summarized as flexibility, readability, and multi-functionality. It focuses on the goal of readability. Paper-like readability should be accepted as the most important target of electronic paper. A concept of readable electronic paper is proposed , and its expected properties, style variations, applications, and various candidate technologies are summarized. As an indication of the realization of readability, an evaluation of user comfort when conducting reading tasks on paper and an LCD shows that free handling of the medium is an important factor in achieving excellent readability.