Stereolithography (SLA or SL; also known as stereolithography apparatus, optical fabrication, photo-solidification, or resin printing) is a sort of 3D printing technology used for layer-by-layer creation of models, prototypes, patterns, and production parts utilizing photochemical processes in which light causes chemical monomers and oligomers to cross-link to form polymers. Those polymers then make up the body of a three-dimensional solid. Stereolithography can be used to build prototypes for new items, medical models, and computer hardware, among many other things. While stereolithography is quick and can make practically any design, it is also costly.