Specialty Greeting Cards business. When people need to say more than "Happy birthday, Mom," they turn to specialty greeting cards. Business Overview Millions of greeting cards are sold annually in the U.S., and starting a business that designs and produces one-of-a-kind custom greeting cards for clients is a terrific desktop publishing business to set into action. In addition to a high-quality color printer, you'll also need a computer and design software. Ideally, marketing...