In column layout "Save to PDF" fills columns differently from display.
I am trying to print html as a book using Paged.js and discovered that fonts are rendered slightly narrower when processing "Save to PDF", which means more characters fit on one line leaving too few characters for the last line on the page to justify, making it too stretched out.
Looking for the root of the problem I made a simple page with multi-column layout and "Save to PDF" breaks up the text differently there, too.
CSS for it is:
width: 500px; column-count: 4; column-width: 100px; font-family: Arial, sans-serif; text-align: justify; text-justify: inter-character;
In the picture is a screenshot of the display at the top and screenshot of the pdf below. They came at different resolutions so I aligned them as best as I could. In this case browser puts "ex ea commodo" in the second column on one line but in pdf "commodo" goes onto the next one.