Black magic or white?

This morning’s Observer column.

What comes irresistibly to mind the first time one sees a 3D printer in action is Arthur C Clarke’s famous observation that “any sufficiently advanced technology is indistinguishable from magic”. You’re sitting there watching the machine busily going about its business and then, suddenly, there’s a complex, fully functional object with moving parts – for example the roller-bearings that are an essential component in every thing that runs on wheels. And then you realise that this is not a technology for making toys and garden gnomes, but something that could transform manufacturing.