Art is Therapy $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". Art is Therapy quantity Add to cart SKU: 188. Category: Hearts. Related Products It’s not Which Way We Face $20.00 Wishing You a Bee-You-Tea-Full Day $20.00 Squeeze the Day $20.00 Chocolate for My Bud $20.00