If you’ve read the segment over about metal foil stamping, the method will probably be straightforward to picture. Within the stack of elements: your cover on The underside. Above it the (optional) foil and after that the metallic stamp (die) using a reversed Model of your kind or design protruding. https://selfpublishinglondon.blogspot.com/2024/09/a-book-cover-design-can-make-difference.html