Outside the world of manufacturing, where mass-produced goods may still have a substantial cost advantage over custom-printed ones, 3D printing will have far greater impact downstream, in the market for spare parts and replacements, where demand is less predictable but more precise. (If you want a widget, any widget will do, but once you have widget 94303, only part 94303A will satisfy you.)
在制造业之外——在制造业，大规模生产或许仍将保持对定制打印商品的巨大成本优势——3D打印将对下游产生巨大的影响，对备用和替换零件市场也是如此——其需求将更难以预测，但更加精确。（如果你需要一个小物件，那么只要是这个物件都符合你的要求；但如果你有了物件94303，那么只有零件94303A才符合你的要求。）