We have developed an interactive pop-up book called Electronic Popables to explore paper-based computing. Our book integrates traditional pop-up mechanisms with thin, flexible, paper-based electronics and the result is an artifact that looks and functions much like an ordinary popup, but has added elements of dynamic interactivity. This paper introduces the book and, through it, a library of paper-based sensors and a suite of paper-electronics construction techniques. We also reflect on the unique and under-explored opportunities that arise from combining material experimentation, artistic design, and engineering. Author Keywords Paper computing, pop-up book, paper-crafts, paper electronics, conductive paint. ACM Classification Keywords H5.m. Information interfaces and presentation (e.g., HCI): Miscellaneous.