When to use wet sanding?

This will sound a stupid question but what factors determine when to use wet sanding?
I find a lot of time i can buff out a lot of scratches with a rotary polisher.
I thought trying with buffer first reduces how much clearcoat I'm removing but maybe not.
Or does this depend on hardness of clearcoat?
Any comments hugely appreciated
Thanks

Most sanding is done on CUSTOM paint because custom paint is thicker than factory paint and you're a LOT less likely to sand and then buff through the clear layer.

I type this all the time, when you sand,

Sanding removes paint
Compounding removes paint
Polishing removes a little paint


Now read these two articles and I think the pictures in the first article will share how risky this is on factory paint.


Clearcoats are thin by Mike Phillips


Wetsanding - Fresh Paint vs Factory Paint



No words can express the heart sinking feeling you get when you discover you've sanded or buffed through the paint.


If you are going to sand on factory paint then stick to 3M Trizact #3000 and #5000 or Mirka Abralon #3000 and #4000


:)