Apparently $20.00 Inside Message Inside: A Parent Packages of Heartstrings® cards are shrink-wrapped and sold in sets of 10 cards with envelopes. The actual card size is 4 1/4" x 5 1/2". Apparently quantity Add to cart SKU: 20. Categories: Baby - Parenting, Women. Related Products My Heart Goes Out $20.00 I Only Have Irises for You $20.00 Whine Bottles $20.00 Sweet Thanks $20.00