Can't see drawing in print preview

dellus wrote

On my printer the widest not printable border area is 5mm.

Same for me but I'd think 5mm is too narrow for a default. I suggested 10mm, 6mm would reasonably translate to 1/4".  I appreciate this needs discussion.

It's only a default the user can easily change but in my opinion the example I provided shows a 0mm default margin is unreasonable.

dellus wrote

I usually draw a paper sheet sized frame around the contents, according to the intended scale. With default margins at 0, as it is now, Fit to Scale automatically scales and places the drawing correctly on the sheet. This would be lost if a margin larger than 0 is applied. But well, this still can be done manually.

If the frame is part of your drawing and you wanted to print on paper I'd expect by default it should be visible on the output. As you say, it's not hard to reset margins to 0mm if that is the intended use.