H2O $20.00 Inside Message Blank Inside 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". H2O quantity Add to cart SKU: 727. Categories: Gardening, Hearts. Related Products Once in a while, I dig in my heels $20.00 Grow a Friend $20.00 Plant Peace $20.00 Blue Columbine $20.00