Thanks Rich! I wish I was motivated to recreate this effect with exact measurements...................unfortunately I'm not.
I really could not find a good video on making complex multiple selections, so I will try to demonstrate with simple shapes.
Here I have 3 shapes on their own separate layers. A white rectangle, a yellow rectangle, and a blue circle/ellipse. All on a grey background.
Let's say I want to remove the Yellow and blue shapes from the white shape.
First I place a layer mask on the white shape layer.
I can select the yellow rectangle by holding the command key and clicking the yellow rectangles thumbnail.
What about the blue circle?
I can make 2 different selections to also include the blue circle into the yellow rectangles selection.
If I hold down the shift key and the command key at the same time and then click the blue rectangles thumbnail, it will add a selection of the blue circle to the yellow rectangles selection.
If I hold down the shift key, and the option key at the same time and then click the blue rectangles thumbnail, it will add a different selection of the blue circle to the yellow rectangles selection.
So now if I turn the yellow rectangle layer and the blue circle layer off, select the white rectangles layer mask, and add black to the selection, this is what I get.....
Now to make it a little more complicated, I could invert (shift+cmd+I) the selections of the yellow rectangle layer and the blue circle layer like this....
Now when I select the white rectangles layer mask, and add black to the selection, this is what I get.....
