In a rare glimpse behind the scenes of Apple, it’s revealed that several 3D printers play a pivotal role in their “Top-Secret Input Lab”.

The secrecy around Apple and the development of their products is the stuff of legend.

Which is why it comes as a great surprise when they allowed a journalist and photographer from Backchannel access to their top secret Input Design Lab in Vallco Parkway. This is the hallowed ground where prototype Mac accessories like the keyboard, mouse and trackpad are put through rigorous testing.

Inside the lab is a massive collection of precision tools. And nestled among the huge range of robots, sensors and custom machinery designed to click and tap hardware millions of times over, there’s a bank of 3D printers that plays an important part in the whole process.

Apple loves MakerBot, and Ultimaker, and ColorFabb

Scrutinizing the pictures, we can see several 3D printers and associated kit: one Ultimaker 2, a trio of MakerBot Replicator 2, and a sizeable collection of ColorFabb filament.

This is the kind of product placement that would have any marketing department whooping with joy — and Colorfabb certainly will be — but the other two brands might be disheartened to learn that neither product appears to occupy pole position in the hearts and minds of Apple personnel.

But contrary to expectations, these machines are not being used to rapidly prototype the next Magic Mouse or Magic Trackpad. Instead, they’re used to provide the testing team more flexibility when putting new products through their paces.

Apple is 3D Printing Custom Cradles

According to Backchannel, they’re primarily used to 3D print “custom cradles to hold devices at optimal angles for testing”, so they’re better able to put specific pressure on specific parts.

This isn’t the typical use case for a 3D printer, where they’re deployed in the early development phase of industrial design. But where Apple leads, others typically follow, so we won’t be surprised to see more examples of this kind of product testing in the near future.

And of course, it’s a matter of record that Senior VP of Design Jonny Ive prefers to use CNC milling machines when it comes to rapid prototyping. Apple certainly has enough spare change to put a couple of those in his design studio.

But what’s slightly more baffling is why they chose consumer-grade 3D printers for their Input Design Lab. Does Apple know something about the capabilities of these machines that we don’t? Or have they hidden away the industrial 3D printing machines in a back-room, away from prying eyes? We may never know.