I’ve been struggling with Writer (LibreOffice) to put a full page background to make a book for my last novel. All the solutions I’ve been offered left margins blank, until a very clever dude sent this to me through the Fedora group in Telegram.
The Workaround is as follows:
Go to Format -> Page -> Page Format and set all margins to 0 (zero). It will show an alert but just click yes and Apply. Then open Gallery and select the image you like, as you can see in this picture:
Alternatively, you can go to Page -> Area -> Fil and there pick what you like as background from the drop down menu.
Then you write some text and select it. Double click on the top ruler and set margins to your text like in the image below:
That leaves with a reasonable text to write with margins and everything over a full backgrounded page like in real books.
And the best!!! It works for all the subsequent pages you add. After, you can add a title page, index, text, and everything else and it will work quite nicely.
Hope this helps!
Thanks to @Voidspacexyz !!!