Let's go through it step by step. With a 300g (unstrung) racket for intensive use such as the Artengo TR990, for example, the weight is distributed across its various sections as follows:
NB: When we talk about adjusting the mass and balance, we're referring to adding material to meet the product leader's specifications.
The addition of an overgrip (3-4g) and a dampener (3g for a conventional round one) slightly changes the weight of a racket.
Please note that racket weight is measured without the strings.
Strings significantly alter racket inertia, by 35 percent or more (see the article on tennis racket inertia). It is for this reason that they are not included in racket weight.