Chuck Hull invented stereolithography, the first form of 3D printing, in 1983. The process involves using a UV laser to cure and harden layers of photopolymer resin, building a three-dimensional object from the bottom up based on a digital file. This 'additive manufacturing' was a radical departure from traditional 'subtractive' methods like milling or carving, where material is removed to create a shape. While initially used for rapid prototyping in engineering, 3D printing has expanded into medicine (printing dental crowns and prosthetic limbs), aerospace (printing lightweight engine parts), and even construction. The invention has the potential to decentralize manufacturing, allowing products to be printed on-demand locally rather than being mass-produced in factories and shipped across the globe.