Polyjet technology produces amazingly realistic wind tunnel test models that can be printed hollow, lighter, and with less material. Inserts, often stock parts, can reinforce the model if needed, contributing greatly to its dimensional stability. Generally, it’s best to use the largest–diameter rod or thickest plate possible while reaching close to the tip of the model. The transparent materials available with PolyJet 3D printing can be useful when evaluating the flow characteristics of internal structures. Combining these materials with the complex internal structures that additive manufacturing allows lets designers verify complex internal designs.