How 3D Printing Works
Most VSR Products are made using Fused Deposition Modeling (FDM) 3D Printing. This is the most common form of 3D printing as it is the easiest, cleanest, and most versatile process currently available. Read more about FDM below.
In FDM, an object is built by selectively depositing melted material in a pre-determined path layer-by-layer. The materials used are thermoplastic polymers and come in a filament form. We use a variety of materials, varying from PLA to Polycarbonate. Also, it is important to understand the drawbacks of the FDM process.
Support Material
As objects are built up layer by layer, the process required a surface to support the material. The melted thermoplastic cannot be printed into thin air. This means that in order to produce certain shapes, the printer will print itself material to hold up the shape of the final part. All VSR Products have been designed using state-of-the-art CAD (computer-aided design) software, and then ran through multiple 3D printing programs (caller "slicers") in order to optimize the production and quality. However, some of our designs must be printed with supports.
All supports are removed prior to packaging, so there is no additional post-processing required by the customer. Supports help gurantee the success and strength of FDM 3D printed parts, but they do leave visual cues they were there even after removal. The surfaces where the support material meets the part material is visible because the surface layers will not look as "pretty" as the other surfaces. This rougher surface does not reduce the tolerance, strength, or performance of the part, it is only a mark showing you that we take all precautions necessary to make the best products possible.

This diagram, image, and description is from the 3D Printing website 3D Hubs.com.