The Continuous Liquid Interface Productiongo technology (CLIP) process relies on a special transparent and permeable window which allows both light and oxygen to get through. Think of it as a large contact lens. The machine then is able to control the exact amount of oxygen and when that oxygen is permitted into the resin pool. The oxygen thus acts to inhibit the resin from curing in certain areas as the light cures those areas not exposed to the oxygen. Thus the oxygen is able to create a ‘dead zone’ aa4within the resin which is as small as tens of microns thick (about the diameter of 2-3 red blood cells). In this subsection of the resin, it is literally impossible for photopolymerization to take place. The machine will then produce a series of cross sectional images using UV light in a fashion similar to playing a movie.

via Carbon3D Unveils Breakthrough CLIP 3D Printing Technology, 25-100X Faster – 3DPrint.com.