I created images twice the size of that standard images to put on my buttons, and I named them "firstname.lastname@example.org". I create my dialog with interface builder and set the image to use name.png. When I try this with a small test project, the high rez images are used when I move the dialog to a scaled HiDPI monitor. With my larger project, it simply won't work, the low res images are always used, but Images I on a toolbar in the same program do switch between high rez and low rez. So, it's not because I use the Display Manger or Carbon or Quickdraw because in that case the toolbar images would also not work. What could be the reason for this? I tried everything I could think of.