Amateur vs. professional

How does the professional painter differ from the amateur?
I've been painting many years but not for a living. What are some of pre-requisite for professional painter? I will be thankful for any answers. My email is [email protected]

[Cynthia Daniel]

I would say simply that a professional is someone who is making money at it.

[Carole Chalmers]

The Washington Portrait Society (no longer in existence) had three categories - Amateur, Semi Pro and Professional. This was based on the percentage of income derived directly from your art. They are the only ones I know of to have such a distinction.