Many cosmetics companies do not manufacture the cosmetics they sell. 
The cosmetic companies buy the products from manufacturers and then
brand and market the products under their own name. I need to know
which manufacturers produce the nail polish sold by:
 
1. MAC (http://www.maccosmetics.com)
2. OPI (http://www.opi.com)
3. Hard Candy (http://www.hardcandy.com/)

I need the name and contact information for the manufacturers.  Thank
you.

bcc8 - 

This kind of information could be extremely difficult to uncover.
Obviously, the companies would not be forthcoming with it - the
private brand manufacturers, however, will often gloat about the
accounts they have...

Good luck.
ragingacademic