I also created the cover for my novel Fire Light, using mostly with Paint.NET.
I just tried to find a way to justify text on both left and right.
I am assuming that this option is still not implemented in PDN as I cannot find it.
I ended up using Gimp and saving to a png file and then opening that in PDN and copying it. Kinda painful. But GIMP 2 also had a bug. The rightmost characters were slightly cut off using Garamond because my first letter in my paragraph was J.
Has anyone implemented the ability to justify text to both left and right yet?