By AppleInsider Staff

Published: 09:35 AM EST (06:35 AM PST)

In an effort to make its next-generation iPad lighter, Apple could replace the device's existing aluminum enclosure and instead make it high-strength carbon fiber, a new rumor suggests.

As he is wont to do, John Gruber of Daring Fireball made the comment in the footnotes of his latest post. However, he cautioned that he is not 100 percent confident in the rumor, which is why it was placed in the footnotes.

"I could publish things I'm only half-sure about, like the iPad 2 switching from aluminum to a lightweight high-strength carbon fiber body, but I don't, because I'm only half sure and I've only heard about it from second-hand sources who themselves are unsure about it," he wrote.

"And even if I were to off-handedly mention such speculation, I'd do so in a footnote and take pains to emphasize the uncertain nature of the information and the second-hand status of the sources thereof."

The post was made largely in response to a new report from Engadget, which claimed that "engineering issues" forced Apple to remove features like an SD card and Retina Display from its second-generation iPad. Gruber himself previously responded in January and said claims of a high-resolution Retina Display on the next iPad were "too good to be true."

This week, he added that "nothing" has changed about the iPad 2 since January. He said it's very uncommon for major features to be axed from a device from Apple at the last minute, as "most major Apple products are pretty stable two months out from release."

For its part, AppleInsider reported in January that the next iPad will not have an SD card slot or a Retina Display.

The most prominent example of Apple removing a feature from a new device just before its introduction came in 2009, when Apple planned to add a rear-facing camera to the iPod touch. AppleInsider first reported just days before Apple's media event that technical issues forced the company to scrap the feature.

As for the rumor about a carbon fiber enclosure, a patent application discovered by AppleInsider last November highlighted Apple's interest in using the material to create a lighter iPad. The Cupertino, Calif., company has shown interest in using either a layered carbon fiber material or a spine or frame used to support a carbon fiber skin.



Apple could mold a supportive spine to a carbon fiber skin for a unique implementation of the material, in order to address issues where carbon fiber can crack or break if bent or rolled in a certain way. Apple's patent application, which shows an iPad-like device in its accompanying illustrations, notes that devices with a metal back are durable, but can be heavier and more expensive.

Apple showed interest in building a carbon fiber MacBook Air in 2008, in an effort to make its diminutive notebook even thinner and lighter. Carbon fiber is an extremely lightweight material comprised of very thin fibers about .005 to .010 millimeters in diameter and composed mostly of carbon atoms.