I'm new Paint.net user so I don't now if this has already been discussed. Paint.NET is light and almost perfect but missing some key features.
1. Right click menu.
2. Smooth brush. It is very important, especially for eraser.
3. Free rotate selection/selected pixels by mouse on edge, not Ctrl+Shift+Z.
4. Magnetic lasso – this can be useful to someone.
5. Brush size slider on right click.
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