Sculpteo says that it uses a "mix of physical and chemical" processes, though it wouldn't elaborate more on the patented system. It appears to be similar to acetone or alcohol smoothing techniques used on extruded objects produced by home 3D printers, however. It's now available in beta, so if you have something to print that needs the extra treatment, you can order it on the company's site . Just keep in mind that it'll add extra cost (and several days) to your project.