Further to the question of how to show glitter on greeting card mockups, here is a real example of one of my greeting cards that has a pearly foil pattern in the background, on the text, and embossed flowers. When I created this card, I had four printouts from the layers in my Adobe Illustrator file…
2) The Foil Layer shows where glitter or foil stamping will be used. Note that when you go to send the design to a printer, if there is more than one colour of foil used, you will need to make separate layers in your files for each colour.
3) The Emboss / Cup die Layer shows the outlines of what shape needs to be created with the emboss.
4) The Mockup shows where the foil and emboss layers are meant to line up with the printed image below.
If you are sending a card design to a greeting card publisher and wish to show foil, glitter, or embossing, the simplest way to do it is to show it in black printouts separately from the design itself. You can find more of my greeting card tips here.