Maybe it's because I have a mind-dulling headache today, but I'm just not seeing the way to either create an inverted vector mask or invert an existing one.
For example, in the following layer stack, I'd like the vector mask on the group to create a transparent hole in the image, rather than make the outer part of the image transparent. Note that the [Invert] button in the Properties panel is unavailable (grayed-out).
If I could have created the vector mask in the first place using the rectangle tool, but inverted, that would have been okay as well, but somehow the sequence to do that escaped me as well.
I know how to do this with a selection, but I'd rather keep it in vector land.
Target the Path and set its combining mode to Subtract.
Thank you. That's the traditional way. I had tried it before, but apparently I either didn't hit the path with the Path Selection Tool first or something.
More Advil is needed.