The common conception about 3D-printing, depending on who you ask, is either that it's a technology that's been used by many companies for several years to make quick prototypes, or that it's a new-fangled hobbyist technology that allows geeks to programme and model pretty, but not entirely useful objects, and then print them out.

Yet 3D-printing is now fast evolving from being a product designer's best kept secret to being a key tool that has the power to not just advance manufacturing methods but completely disrupt traditional industry processes and business models.

Take Normal, a new start-up that already has a large retail store in Chelsea, Manhattan, a multi-cultural area in New York where art galleries and alternative shopping reign supreme.

The business model centres around personalised earphones that fit properly, and the company can make these products instantly on 10 Stratasys Fortus 250mc 3D printers, using information sent by customers from an iOS or Android mobile app.