The post cards are the perfect size for hanging earrings and pendants. However I haven't figured out how to string the pendants and make them look good on the cards. I guess for now I'll just added the necklace to the bag.
I also ordered more business cards to use as earring hang cards. My other cards have color on the back and the earrings get lost in the confusion.
The only drawback is that holes are punched into the image on the back. On the postcards that's not a huge deal.