easier to do. Don't know why the edges are so sharp on the copy/paste.
Sigh...I know. It's embarrassing and frustrating for the very fact that I thought that splitting it the way I did should have made it
In addition to changing the background color, always work at a larger size if you're going to be doing postwork copy and paste, or if you're going to be hand drawing things into your renders.
For example, if your final picture is going to be 100 x 100, change your render settings so it will render your pictures at 400 x 400.
Do your postwork with the 400 x 400 pictures, then export your final image back to 100 x 100. By shrinking the picture, the jagged edges will be too small to be seen. This is a technique used in the comic book industry to get smooth digital lines (Anti-aliasing makes the colorist's job harder).