Stereolithography (SLA)

What took weeks, even months, just a few years ago can now be done in a matter of hours using SLA technology.   Prototypes are built by passing a laser over a vat of resin and "growing" the part layer by layer.

Once the first layer is completely traced by the laser, it's lowered a small distance into the vat and a second layer is traced right on top of the first.   The self-adhesive property of the material causes the layers to bond to one another and eventually form a complete, three-dimensional object after many such layers are formed.