Unlike a sculptor who chips away at a block of stone to reveal a shape underneath, 3D printers work in the opposite way, building up physical objects by adding material layer on layer.

与雕刻家凿下石头碎片后所展示出的形状不同，3D打印机以相反的方式工作，它通过一层一层地添加材料来构建实体对象。