In the long history of human civilization, few materials have so profoundly reshaped our way of life while also prompting deep ecological reflection as plastic. Born in 19th-century laboratories, this synthetic material has, in just 150 years, evolved from "Celluloid"—a substitute for ivory—into everyday items that permeate every corner of modern life, ultimately becoming a serious challenge to our planet's ecosystems. So, who first invented plastic? Let’s trace the timeline and meet the key figures essential to plastic's development.