Andy Bailey is a stop-motion animator at Laika who worked on Kubo and The Boxtrolls. In this video, he shares his process while making a 658-page flipbook called The Return of Grumpy Cloud that took him 35 work-days over three months to complete. The end result (skip ahead to ~14:25) is pretty impressive given the lo-fi medium. Bailey sells kits for making your own flipbooks, but the store was down for maintenance when I checked.