Adding background images to handouts

I am creating handouts for a game where the handout text for lore is subject to relatively frequent edits (I move text from the GM section to the Player section as it is discovered, skills improve or events occur in timelines)

This works fine but looks hideously plain and non-atmospheric.
I could make static images combining text and graphics but I really don't want to, given that I do not want to juggle multiple  jpg copies of each lore item each with slightly different text

So what I am after is embedding a jpg as the background in handouts.

This used to be possible via CSS. DOM and/or HTML editing but is apparently not any more (having tried it multiple ways) - is this something that could be done through the API or a macro, is it doable that way but I am not trying the correct method or am I after the impossible?

If impossible are there any other methods that people have used?

(previous method https://www.reddit.com/r/Roll20/comments/9tfler/roll20_handout_character_info_editor_is_a_wysiwyg/ )

Thanks and all that

It would require that the game creator have a pro subscription, but there is an api script that looks like it allows a lot of handout customization.  I haven't used it, but some things that people came up with and posted in the thread look good.

https://app.roll20.net/forum/post/8028597/script-markdown-handouts-and-bios/?pagenum=1

Thanks - that does look like what I want - and will probably tip me over to pro if a second reading is as good for me as the first skimming.