Go to Hallmark's contest website and review the list of their current contests to see if your work would qualify. Contests are the only exception Hallmark makes for unsolicited manuscripts.
Read the contest submission guidelines carefully. Upload your cover work into a photograph editing software on your computer and resize it to the dimensions specified in the contest's guidelines. The exact dimensions may vary depending on the contest and the type of card.
Click on "Enter Now" for your chosen contest. Read the terms and conditions carefully, then click "Upload" and select your card cover from your computer's photograph editing software. Copy and paste or upload any writing or poetry for the inside of the card into the specified box on the contest page and click "Submit."
Find a literary agent to represent you. Hallmark accepts material from literary agents. Go to an online literary agent listing site, such as the "Writer's Digest" or "Writer's Market" websites.
Read each agent's submission information and make sure he accepts greeting card materials. Follow each agent's guidelines for submission. For instance, some may just want a letter describing your greeting card ideas, while others may want you to send an example online.
Wait to hear back from the literary agents you contacted. If a literary agent wants to represent you, she will contact you for additional information and material and then send it to Hallmark on your behalf.