Starts at a bottom plane and works its way up layer-by-layer depositing either a support structure or a special plastic until the entire model is complete. The support structure is then washed away and the remaining part is an exact-scale prototype of your part.
Using a 3D CAD model we can print your part out in the actual size and shape it was designed. We achieve this is using FDM (Fused Deposition Modeling). The 3D printer

There are some minor drawbacks to the prototypes. Since the layers are around .010″ thick, the parts tend to have a stepped texture – particularly along curved surfaces. This can be minimized through post-process techniques such as sanding and filling, but for most applications it is an extremely minor issue. Also at issue is the relative frailty of the parts. Being used to injection molded thermoplastics, most people are surprised when they find they can break the prototypes apart with their hands. Unfortunately the layering process does not allow for the same internal bonding to occur as it does in traditional methods, but a little care – especially with skinny features – will ensure that you prototype remains intact.