The first 3D printers were created in the late 1970s, and were bulky, expensive and rather limited. As time passed, this early 3D printing technology has been improved upon, to the point where nearly anything can be created, from small rubber-like parts, to artistic sculptures. A variety of additive processes have been developed to make this possible. Here are a few of them:
Selective Laser Sintering (SLS): This method melts or heats material to soften it, building the models, layer by layer, in a melted or softer material that will harden once it is deposited.
Fused Deposition Modeling (FDM): This method functions similar to SLS, above, and softens materials before depositing them, which causes the layers to fuse with each other, permanently, as they dry and harden.
Stereolithography (SLA): This method cures liquid materials by using more sophisticated technology, such as an ultraviolet laser, to create the final hardened model.