The report said that Apple is still not satisfied with the low weight of this model which they claim is one of the thinnest laptops in the world.
The company is said to be considering using carbon fiber for manufacturing some of the parts of the MacBook Air.
Carbon fiber is extremely light weight but retains the strength. It is used on aircraft bodies.
Incidentally, it is also used by some other personal computer makers including Sony in some of their notebook models.
This could reduce the weight of the laptop but is certain to increase the manufacturing cost of the MacBook Air.