The idea was first demonstrated in the mid-80s, although the term 3d printing didn’t appear until the mid-90s, A number of different technologies car be used, but most work in a similar way. A design is created on computer, often by scanning an existing object. A laser passes over the object and creates a 3D picture of the shape. The shape is then broken down into layers. Each one is only about 0.1mm thick, and the object might be made of thousands of them. The printer makes the object one layer at a time.