In the February 12th 2011 issue of The Economist, there’s a fascinating article about 3D (or additive) printing. In the book business we have become used to the idea that we live towards the low-tech end of the print industry. Microlithography for printing computer chips has made us look a bit crude for years. Now there’s 3D printing. There have apparently been machines out there for about 10 years to make a cheap prototype. These machines are now ready to move into the finished product end of the business. Wikipedia has a good entry which already contains a quote from The Economist article.

The glove which they illustrate was “printed” by Within Technologies, a London firm, and can be made in nylon, stainless steel and titanium. So when you next need that iron fist, you won’t have to wrestle with knitting it in stainless steel yarn. There are different types of printer. One type works a bit like a copier: directed by a detailed computer program it deposits a thin layer of powdered material, bakes it, and moves up to the next level doing the same again. The “baking” can either be done by a squirt of liquid blender, or by sintering with a laser or electron beam. Other machines deposit filaments of molten plastic. One additional benefit of the technology is that surplus powder can be reused, cutting down drastically on waste.  As compared with old methods of making machine parts, which involved starting with a block of metal and cutting away and discarding, the bits you didn’t need*, this method uses only that material which is essential to the structure of the piece. Apparently parts can be about 60% lighter: important in aviation where a reduction in weight of 1 kilo can save about $3,000 in fuel over a year.

* swarf is the word for this stuff — the little twirls of metal machined away from a block.