My document prints okay (exactly as it appears on the screen in Libre Office), but when I export to PDF and view the PDF on screen there are white borders around each text or picture object.
Here's a sample snapshot from PDF/Preview:

I've tried selecting a paragraph and changing the border property to None as described in Libre Office help, setting the "Line arrangement Default" to "Set no borders".
But borders set by the Format dialog don't correspond to the borders I see in PDF/Preview. In PDF/Preview the border appears on line boundaries. Borders set in Format appear around each picture, for example.
What am I doing wrong?
