It has been suggested that the cards look better with no text in the tweet. Of course that makes it hard to search for the cards. Your choice. :-)

When posting to Facebook, you can add a description to your cards. Descriptions will only appear in the Facebook posts, not in Twitter.

You can choose a logo from this set of Emoji characters.

The canvas is 800 pixels wide by 600 tall. If your image isn't proportional, we'll add blank space above and below. If you'd rather have the image stretch to fill the canvas, check the box.