As a result, some limitations exist within RP, such as Size envelopes. Larger parts can be quite expensive. Limited material properties. Many argue that RP doesn't equal or rival injected molded parts. Because parts are built in sections, the properties may not be very isotropic.
Surface finishes that require subsequent finishing labor.
This is due in part to the accuracies of the technologies and can sometimes be caused by using too coarse an STL file. Materials development RP vendors continue to make significant strides in material development. During the past year, researchers used water to build RP models out of ice. This could prove very interesting because you can make a casting mold and simply melt the core away. These frames develop properties very similar to real bone.