Mobile eBook readers and reader applications are readily available and are marketed as convenient for accessing personal eBook collections. Different brands of readers and apps are frequently evaluated and compared in consumer, trade, and popular magazines, but rarely in academic studies. This present study examines nine personal digital library (pDL) interfaces, from which design cues are drawn and paper prototypes of pDL for eBooks are developed. The paper prototypes are evaluated in a usability study to elicit the eBook display preferences of users.