I would like to have text flow around the positive space of the background image in my PDF, kind of like the image on the left (from the DnD 5e player's handbook):
I'm not really tied to a particular package or workflow, but the easiest method in terms of content creation would just be to create a B/W mask such as the image on the far right, however I'm not sure how to translate that into a method to control the flow of text. flowfram seems promising, but also seems like a lot of effort for images which will reflow the text using multiple rectangles (I count three just for this sample image).
EDIT: I would like to use this for longer pieces of text with multiple paragraphs, section headers, figures, and so on.
Postscript: Please feel free to tag this question as any specific tags I could think of don't exist.

xgalleyandl3galleyseem like they might eventually be useful. But they are not ready yet. I'd cut my loses and use Scribus. – David Purton Nov 03 '18 at 04:37\parshapeto adjust the way a paragraph will flow. See How to layout irregular paragraph shape? – Werner Nov 03 '18 at 05:43\parshapeis OK if your images are tied to the paragraph, but not if this isn't the case. – David Purton Nov 03 '18 at 06:55