We’ve gotten requests for flat card sizes at-a-glance. Click here for a downloadable pdf for easy reference. The card sizes show for custom stationery printing are the most commonly used and bestsellers on our site. A9 and A7 cards are typically used for wedding invitations and baby announcements but they could also be used for personal stationery. A6 is commonly used for thank you notes and monogrammed stationery for adults or kids. 4″ x 6″ cards are great for postcards, info card for wedding suites or thank you notes. A2 is our most popular size for custom printed notecard sets, wedding info cards and invitations to more casual events such as children’s parties or housewarming. 4 Bar Cards are frequently used for reply cards in a wedding suite. Custom printed business cards are for, you know, business 😉