Thanks for the information about DesignSpark CAD. I've worked with Solidworks, among others, and I've found it good for one-off work.

I think something was lost in translation when I asked about casting. It's not the molding material, but a hard, low temperature wax. It's formed into the net shape, embedded in the molding material, and then burned out leaving a perfect cavity for the molten metal. After the metal is poured and cooled, the mold is broken and the part removed. It's used to make metal parts with extremely complex geometry i.e. turbine blades with internal coolant conduits.

Up until now, it required assembling individual wax parts to make the wax investment. 3-D printers could manufacture the investment as a single piece if extrudable wax media was available.

EDIT: Saw your update. That was the information I was looking for. Thanks.

Don't worry about the "investment" nomenclature. Technical terms tend to have very specific meaning that don't necessarily line up with the layman's definition. Get an engineer to explain the difference between load (total external force as a vector), pressure (external force per unit area as a scalar), and stress (internal force per unit area as a vector or a scalar depending on the definition) if you want an example.