CAD files have a myriad of formats and corresponding file extensions (example: filename.extension.) With all those formats out there, what is best for you to use? CAD files for 3D printing generally fall into two categories: parametric files (equation driven files that are fully defined - i.e. a circle is actually a circle) and mesh files (made of points and triangles - i.e. a circle is thousands of tiny triangles.) Here's a great guideline. to help you get started.
3D Systems (DDD) just announced their first full color, yet flexible material system, the Projet 4500. Based on the video, it seems pretty impressive, but like all new product announcements from 3D Systems, we don't get much real information.
Currently there are only two full color printers on the market today, the Projet 660 and 860 (formerly ZCorp 650 and 850 prior to DDD's acquisition of the company.) Due to their powder bed and HP print head technology, the systems squirt varying amounts of cyan, magenta, yellow, black and clear binder into each layer to create a color palette of almost 400,000 colors. The powder is polymerized to adhere together when the binder is infused, but is really nothing more than glorified plaster of paris.
Afterward, parts are generally infused with cyanoacrylate or Epoxy to brighten colors and add strength. The final parts are tough, but have very little elasticity - under 1% elongation at break. That means the parts are very brittle upon high impacts and important design features that require flexibility, like snap fits or springs, do not work.
Although the Projet 4500's 10''x10''x8'' build chamber is significantly smaller than it's older brothers (660 is 50% larger at 15''x10''x8'' and 860 is about 240% larger at 20''x15''x9'',) the printer boasts a palette of over 1 million colors and the ability to produce flexible parts. Layer thickness of .1mm (.004'') and build speed (some of the best in the industry) seems fairly consistent with all the three printers.
By far the largest game changer is the ability to make flexible parts, because all other systems on the market today that make plastic with flexibility are limited to monochromatic or white color. This may be a feature that is backwards compatible with the 660 and 860, though, since the concept behind the 4500, namely squirting colored binder into a bed of white powder and curing it, has apparently remained the same in the new system.
The real change here may just be in the release of new materials to put inside the printer: a polymer powder, new binders, and improved curing infiltrants.
Whether full color flexible materials are available for all full color Projets or just the new 4500, the increase in flexibility and therefore durability can make powder-binder machines some of the most desirable in the coming years.