@burnout426
you might be right. This could be the problem, as Opera uses the chromium engine. Probably also in the print to pdf feature. And if this feature takes the paper size from the web pages css, there is no chance to fix it in Opera's (or Chrome's) printing dialog

@leocg
Could it be that web pages change the paper size? The pages I print ar often from German but also often from US-Websites (EurekAlert! etc)

@leocg
My printers are set on DIN A4, even Windows' own "Microsoft print to pdf".
But usually I use the "save as pdf" function of Opera.
The strange thing is, sometimes DIN A4 is still in the print dialog and sometimes it changes again to Letter. So I hoped I could somehow change the standard settings and save my changes as new standard.

Is there any possibility to change the settings for paper size an page margins permanently? I use version 72.0.3815.186 and ever again the size changes to "Letter" (I need DIN A4) and the margins go to some minimum value. In some earlier version at least the paper size stayed on A4.