Printing Real Things

A 3D printer does not print words on paper. Instead, it builds real objects, layer by layer, usually out of melted plastic. You start with a design on a computer, and the machine slowly turns it into something you can hold. People print toys, phone cases, and spare parts for machines. In hospitals, doctors use 3D printers to make models of bones before a difficult operation. Some companies are even trying to print houses. Printing an object can take many hours, and the result is not always strong. Still, this technology gives ordinary people the power to create almost anything at home.