PS: the first two background images I had edited to make the canvas larger, and the actual image on the left top, trying to figure out how this works.  It seems the menu puts the images a little higher than the actual menu is drawn. 

Yes.  Here are comparisons of that checked and unchecked.  It stretches it no matter what.  I don't want it to stretch at all..

The original size at 100% is on the left...

I don't know if it makes any difference, but I have my Start11 Menu at the top of my screen, and it has always worked fine there.

I understand what you mean.  So, I resized the image to just a bit larger than the Start Menu background, and it still is stretching it.

It would be nice if the developer could give some instructions on how to make a background.  What are the rules to follow?  I am trying to make my background 'just fit' into the start menu, with the right-side panel gray, and with none of the image.  I believe I have done it correctly.  But it still stretches it.  

I put the image behind the Start Menu, and lined up the letter D with the cursor.  So the image does align at the top left.  But you can easily see at the bottom, that even though the image is larger than the Start Menu, it has been stretched.  

I assume since all of the 'stock' backgrounds are generic and easily stretchable without screwing them up, that the Dev thought the Background should always be stretched.  Which is very Limiting!!  Argg..

I believe achieving proper alignment is tricky because the Shortcuts list on the right side of the Start panel maintains a fixed horizontal width, regardless of how wide the overall Start panel becomes. If you include the dark gray area in your background design, it will stretch or compress with the panel size—causing it to misalign with the actual Shortcuts section.

I'm not sure if the developers plan to introduce more cosmetic options in Start11, such as assigning different backgrounds to separate areas. 

Thank you,

Basj,
Stardock Community Assistant