Ser & Estar for Physical Appearance

[LJM]

Hi,

I'm working through a couple of textbooks and I'd already worked through Ser and Estar in one of them and thought I understood when to use each of them. However I've just reached the subject in the other textbook and I've found some conflicting information. One textbook states to use Ser for physical attributes and states that despite the fact beauty can fade it generally does not change overnight. The other textbook when giving examples of when to use Estar, says Él está guapo, which is obviously means he is handsome. I'm sure you can understand my confusion so would anyone be able to shed some light on what is actually correct?

Thanks,

LJM