Thank you, Teresa, for your answer.
I've been there, but I couldn't find a proper solution to my problems.
I was able to insert underlines/borders, but the thickness was always too thin, even when I changed the parameters the software seems to ignore the settings.
On the other hand, I haven't figured out how to insert just a line/row as a spacer without inserting an element, just a blank line.
The formatting page in the documentation is a bit poor imho, only explains the general settings and mainly headers and footers, which I already formatted as needed and I know all the options there, but there's a lot more that can be formatted and I can't find a good manual (there should be something somewhere, but I don't know where).
That would help.
Thank you!
Best regards,
Luca