Stereolithography (SLA) is a 3D printing technique that uses a laser to cure liquid resin layer by layer. It works by filling a vat with resin and using a laser beam directed by mirrors to cure the resin into solid plastic shapes according to a digital file. The build platform then lowers into the vat to begin the next layer, and struts may be printed to support overhanging areas before being removed after completion. SLA provides high resolution prints from a digital file using ultraviolet light to solidify liquid resin.