RH2020 Background Images Don't Display

[milSkrid]

In previous versions (classic) of RoboHelp, I've added a background image to my master pages, with no repeat. In the current version, although I can specify a background image in the master page (and sometimes see it, although it repeats when I have none selected), I cannot get the image to output and be displayed in the webhelp.

I've looked all over the place using typical keywords and everything I've found tends to gloss over the process or just mentions what to do. I can't find a solution for when it doesn't work as advertised. Any ideas on what I'm doing wrong?

[Amebr]

Which output are you generating? Webhelp isn't one of the types in RH2019 New UI and above - probably you are generating a Responsive HTML5 output unless you deliberately changed to Frameless. (If the icon next to your output preset name is a shield with a 5 in the middle, that's responsive HTML5. The name of the preset doesn't actually tell you what type of output you're generating.)

Also, which skin are you using?

[milSkrid]

Changing from RoboHelp Classic 2019 to RH2020 has a bunch of pitfalls in how your workflow changes.

Turns out that the functionality we used with RHc2019 in master pages, to place a background image at top, was moved to CSS in RH2020. In playing around with our project, I was able to apply a css style sheet to the default master page and one to the title master page. In this way they each have a different image.

Thanks all for the pointers! You put me on the right path.