You are welcome, Jack and Abbie! I haven't tried it yet I have been using GIMP, very interested in trying it. Paint.net has a forum which is a great help and a good sign it is liked and used by a lot of people.
Jack,
I understand the interpretation quality of black and white (probably color too) can vary depending on the different programs out there. Have you heard or experienced it's quality on Paint.net?
Obviously you have been happy with it. Gimp has three choices for black and white interpretation, I've gotten some really nice edits from it. There are programs out there that specialize in the area of black and white effects and can go a lot further, you do pay for those programs of course.