AAAAAA I COULDN'T ANSWER BUT YES! I'D LOVE TO!!

Unfortunately I think those are the only available solutions 😭 most of the golden details in books are still made manually or with big industrial machines 😞

If I may give my opinion: if I'm not wrong, that process can be done after printing, using foil stamping! Expensive? A little bit. I'm almost pretty sure it also has to be done with special ink, so the foil can be glued properly :3