Our models are printed out of the Stratasys Eden 260v and we use the Objet Verodent plus MED690 material, which contains acrylic compounds and provides fine 16-micron layers. VeroDentPlus (MED690), a dark beige material that creates amazingly fine features and finish, and offers excellent strength, accuracy and durability. It is very similar to the PMMA material and feels like a hard plastic material. Here is an image of what the final models will look like.
Here is the composition/information on ingredients for the MED690 material.