What I'm trying to figure out is how they make the dark fringe, I'd assume that they are sewing dark rectangles onto the edge of the document so they stand out. To get that effect you've got to be looking from the right angle and have the right lighting.
https://www.wipo.int/wipo_magazine/en/2018/04/article_0006.h...
There will be a cheaper version of this.
What I'm trying to figure out is how they make the dark fringe, I'd assume that they are sewing dark rectangles onto the edge of the document so they stand out. To get that effect you've got to be looking from the right angle and have the right lighting.