Handed out as part of Google's annual goodie bag for attendees of the I/O developers conference in San Francisco, the Cardboard package came with all the necessary materials to easily assemble a makeshift virtual reality headset.
Google has an entire developers page dedicated to the project, born of two employees at the Google Cultural Institute in Paris, that includes schematics, a materials list, and the project's open software development kit.
Once unfurled, it's easy to see that Google designed its Cardboard package to roll together with minimal effort and no additional tools.
Seen here are all the materials, which Google says you can buy for roughly $20. This includes the $10 lens kit, about $7 worth of off-the-shelf magnets, $3 of Velcro, a rubber band, and a $1.50 near-field communication sticker tag. The cardboard could easily be recycled from a box.
Tearing off the extra slab of cardboard means you're ready to construct the headset in a simple series of motions.
To get the appropriate material consistency if you're making your own headset, Google recommends using E Flute variety cardboard, a distinct kind of thickness for corrugated paper. Or a good alternative is a pizza box. Order an extra large, the company says.
Here at CNET we used a Nexus 5 smartphone for Cardboard, but Google says any device running Android 4.1 Jelly Bean will do.
The NFC sticker tag attached to the cardboard housing should launch the app immediately upon placing your phone inside. If you have trouble, launching the app before you close the housing works just fine.
Before you fasten the Velcro down, once your phone's inside Cardboard, make sure to press the phone firmly against the walls of the board that hold it in position in front of the lenses. The better positioned the phone is, the easier it will be to look through and get a crisp image.
Finding the proper lens kit is the trickiest part, says Google. The company recommends a 45mm focal distance, but it depends on your eyesight.
Google used biconvex lenses from a company called Durovis, found on Amazon, to prevent the edges of the images on the screen from distorting. Unfortunately, it looks like the product, thanks to Google, is currently unavailable.