Will Cosmetic Modifications void warranty/Applecare?

The Topic, "Applecare" or "Warranty" is not listed as a selector option.

Hi,

It would seem doubtful, that companies would disallow

warranty on account of cosmetic modifications, but need to be sure.

If a decal or "skin" is applied to an Apple product (such as

common "skins" that change the appearance of Macbooks)

is permanently applied, would this

cause Apple personnel to disallow performance of warranty work?

Many thanks.