Should you’ve examine the portion over about metal foil stamping, the process might be straightforward to photograph. From the stack of materials: your cover on the bottom. Above it the (optional) foil and after that the steel stamp (die) using a reversed Edition of one's sort or design sticking out. https://professionalbookscoverdesign.blogspot.com/2024/09/how-are-book-awards-and-contests.html