Hats Off To You Birthday Card. Front: Blank. Inside: Hats off to you! Happy Birthday. Size N: 5x7 inches. Artist: Katharine Barnwell. Single Greeting Card With Envelope. By Caspari Birthday Greetings Cards Perfect for Happy Birthday Wishes, Occasions and Celebrations. Find Caspari Greetings Cards, Available and in stock now at the Interior Digs N Gifts Card Shop Online or In store for local pick up.