Marie-Claire, thank you for the kind words on my work. I’m pleased that you and many others notice, as they are meant to be small subtle details, that give that special touch to a page.
Carole refers to that technique as out of bounds. There is a masterclass on it.
Extract the area using the eraser tool. Very very carefully, I might add. Leaving one pixel behind will destroy the effect. Move above the frame. It’s imperative that everything retains its original sizes and position. These are the basic steps. I will use other tools and techniques depending on the project. I u always use a mask when I do extracting. Check out the masterclass called Out of this world.