Because there is no point. No one, is going to ignore the drink in their hand to knell over your personalized napkins. NO one cares if they got personalized matches (except you....). Anything that has your names and date on it will languish in a drawer (like those cute robes, engraved flasks, bottle opener favors).
A cocktail napkin has one purpose; to absorb cocktail sweat. Sorry. Don't spend the money.
A cocktail napkin has one purpose; to absorb cocktail sweat. Sorry. Don't spend the money.