I have recently opened up a topic about base64 encoded images in a custom print format. The problem is that you can embed base64 images in a html print template, but they do not get printed. Although you can see them in the print preview they get removed when you click PDF or Print.
I figured there is a frappe extract image function, which I cannot disable. (There has been a PR a couple years ago).
I consider this to be a real flaw, since using custom print formats with pictures is a common thing. (P.S.: I am not talking about images that refer to a url or similar). Is there really no solution, mitigation for this?