Heart at Work $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". Heart at Work quantity Add to cart SKU: 206. Category: Hearts. Related Products The Plot Thickens $20.00 Chocolate for My Bud $20.00 Starve a Cold, Feed a Retreiver $20.00 The Beet Grows On $20.00