Prototyping is the process of creating a sample product model to be tested in the real world environment and to serve as a basis for other processes.

Traditional prototyping involves designing, developing, building and fabricating a model of our product, typically by designers and developers using pen, pencil and paper or a CAD design software file; while rapid prototyping (RP) involves 3D additive printing of the scaled model of the part or assembly using a 3D printer and a 3D additive layer manufacturing technology, without manufacturing process planning or tooling.

Prototyping is the design verification and adjustment phase of product development since it proves and demonstrates the design. We want to be able to touch and feel, test and demonstrate a product prior to actually manufacturing it either in mass production or from an expensive material and we want to make sure our design suits our needs and applications.

It enables us to display and show the new product, either to our managers, our investors, our designers and/or our customers. It lets us test our ideas and concepts to see if it can actually work in the real world as well as to test the design to see if it passes all the requirements testing. We can also use a prototype to evaluate if and where we need to conduct improvements and changes if necessary.

We can build a partial prototype or we can build the actual part itself, looking and feeling as the complete product. It might function or not, or it might only function partially for testing only portions of the design. The final version will probably look right and function correctly.

So, how is a traditional "old school" prototype be any different than rapid one? The traditional prototyping method includes a mock-up fabrication of different materials, including clay, foam, wood, plastics and metal. It can have additional materials to it such as wires, tape etc. We can create if by hand – cutting, gluing, taping or we can fabricate it with CNC milling machines. On the other hand, rapid prototyping includes technology that creates the 3D part from the CAD file itself (no paper designs) on a computer and 3D printer, using materials such as ABS, PLA, PETT, HIPS, HDPE, PVA, resin, ceramics, nylon, stainless steel and more.

3D printing is becoming more popular recently due to the fact that we can control speed and accuracy of the fabricated parts with it, and we can create highly complex prototypes with it that we might not be able to if machining. The part made with a 3D printer can be almost identical to how the final product will look like, therefor giving a much better sense of the "real deal". Also, there is much less waste material in 3D printing and it is usually a task for one person, thus saving money on personnel and staff. There can be a large number of designers working on the development of a single prototype, making it a challenge, but most of the 3D printing software offer sync options, so everyone can be on the same page.

Once we move past the prototyping phase and we need mass production of the parts rapidly, then the additive manufacturing process is probably less effective and slower (having to produce each layer at a time) than the traditional methods of parts fabrication, such as CNC machining with a CNC router. Also, it is sometimes impossible to use the 3D printer to produce a part that is oversized or of a large-scale, and having to fabricate the parts in sections then glue it together can be a hustle.

However, no matter if we are using a traditional prototyping technology, or an additive rapid one, a prototype serves us as a tool for learning, experimenting, for visualizing and for design improvements and insights. This tool is especially helpful in cases where the end product is very complex and might need several design changes, more specifically in industries such as medical, automobile, bio-engineering, aerospace, marine and more.