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". Chews Gifts Carefully quantity Add to cart SKU: 68. Categories: Birthday, Christmas - Holiday, Pets. Related Products Make time to play $20.00 A Little Bird Told Me $20.00 This Too Shall Pass $20.00 I heard by word of mouse $20.00