Plastic! explores the reuse of plastic waste as a structural and architectural material through parametric design and modular fabrication. Inspired by biological systems and the geometric logic of Platonic solids, the project develops a lightweight dome structure consisting of interlocking 3D-printed modular components. Using Grasshopper, a two-layer triangulated geometry was generated and translated into a scalable assembly system. The project investigates how digital design can transform discarded plastic waste into architectural value, proposing reuse both as a material strategy, and as a method for rethinking construction logic.