Working My Tail Off $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". Working My Tail Off quantity Add to cart SKU: 272. Category: Humor. Related Products Unidentified Frying Object $20.00 We All Seek Higher Peace $20.00 You are the Rock in My River $20.00 Fire Up the Choir $20.00