Coal In One $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". Coal In One quantity Add to cart SKU: 693. Categories: Christmas - Holiday, Sports. Related Products Seasons Greetings from the Rockies $20.00 Vitamin XC $20.00 Claustrophobia $20.00 Christmas Cat $20.00