1. Stereolithography Resin
liquid photopolymers
Different ones with specific properties
optical transparency
UV and humidity resistant
higher strength, flexibility
Used for rapid prototyping

2. Stereolithography 3-D CAD model Software chops model into thin layers
UV laser paints one layer
Platform drops down a fraction of a millimeter
Steps 3 and 4 repeated until done
Placed in an ultraviolet oven that thoroughly cures the plastic.

3. References http://www.stereolithography.com/slainfo.php