Everyone's now aware of 3D printing - they've read about it in the papers, on blogs or seen it on TV. The mentality now seems to be that, in the future, we'll be able to download our products or make them ourselves with CAD programs, apps and 3D scanners, then just print them out, either at home, or in localised print shops. Which in turn will supposedly decentralize manufacturing, bringing it back to the West. But like the cupcake, Daft Punk's latest album, or goji berries, 3D printing is severely overhyped - and I should know, because it's what I do for a living.

People's expectations: They've seen a 3D printed violin; a crazy shoe, and a wrench (yawn) which actually works, straight out of a printer. A very, very expensive, high-end printer which uses lasers or resins. These people think that they can create objects as well without much input or training, on a machine which costs $800 or less. Imagine you'd lived on a planet that had never seen a car before, and all of a sudden the newspapers start reporting about the car, a vehicle which can do up to 250mph, carrying up to 10 people, and cost as little as $300. All true, but as we know, that's not the full story.

The name: '3D printing' makes it sounds so easy, doesn't it? Do you think if it were still called ‘rapid prototyping,' people would be saying “I can't wait to get a rapid prototyper in my house'?

Strength: 3D printed parts are not as strong as traditionally-manufactured parts. Their layer-by-layer technique of manufacturing is both their biggest strength and their greatest weakness. In something like injection moulding, you have a very even strength across the part, as the material is of a relatively consistent material structure. In 3D printing, you are building it in layers — this means that it has laminate weaknesses as the layers don't bond as well in the Z axis as they do in the X and Y plane. This is comparable to a Lego wall — you place all the bricks on top of each other, and press down: feels strong, but push the wall from the side and it breaks really easily.

Surface finish: People hear you can print in plastic, so they visualise a plastic item. This is likely to be gloss and smooth. They don't visualise a matt finish with rough layer lines all over. Many companies offer a ‘smooth' surface finish, but often neglect to add the suffix ‘for 3D printing'. You can also post-process parts, but this generally involves labour and/or chemicals like acetone (really nasty stuff) and loses detail and tolerance on parts.

Cost: Cost is based on material used, so big things are expensive, and small things are cheap. That's it. Nothing to do with complexity, and nothing to do with number of parts. The beauty of it is that there is no tooling — this opens up a world of opportunity to the designer, the creator and the hacker, but does it really help people who just want a replacement door knob? There is also no economy of scale, so one item is $X pounds, and a thousand items are $1000s. So, producing anything in bulk that is bigger than your fist seems to be a waste of time.

The materials are also much more expensive than buying just raw material, with the cheapest being about $50 per kg, ranging up to $500 for some resins. So you're not really making a saving here, I'm afraid to say. Sadly for every request we have for a full sized Daft Punk helmet, there's an equal number of disappointed Daft Punk fans out there, when they find out how much it will cost to build.

Speed: Many people say that 3D printing is quick — this is another omission of a suffix — this time ‘for manufacturing processes'. Items regularly take hours to print, even days. You can speed this up by making the layers thicker, but as soon as you do this, you lose your surface finish quality. The notion of ‘but it'll get faster in the future' is not necessarily true, as we are limited by the chemical properties of materials such as ABS and PLY — these materials can only be extruded so fast, and at such a rate before you start to destroy the properties of the part. This is happening with the top-end machines right now for FDM (Fluid Deposition Modelling).

Usability: This is huge. To print something, you need a CAD model. Getting that is hard. Really hard. When you write a letter, you don't just click ‘print,' do you? You have to actually type it and check it for mistakes. Now this is the same for 3D printing, but a million items harder. So how can you do this, I hear you ask?