Chews Gifts Carefully $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". Quantity Add to cart SKU: 68. Categories: Birthday, Christmas - Holiday, Pets. Related Products King For A Day $20.00 This Is It $20.00 You Are So Good to Me $20.00 Fire Up the Choir $20.00