Across the centuries, humans have loved to celebrate love. From the ancient Roman fertility festival of Lupercalia, to the Renaissance vision of courtly love, to Ophelia’s sad mention of Valentine’s Day in Hamlet, February 14 and Valentines have been symbols of romantic love. In Britain around the 1820s, specially-made papers for sending Valentine’s Day greetings began to be marketed. They became so popular that they were soon being made in factories. Often flat paper sheets printed with colored illustrations and embossed borders, they were designed to be folded up and sealed with wax for mailing. A very fancy Valentine could be made with real lace and ribbons, with paper lace…