For print size, we have a variety of options to choose from:
This poster download provides a JPG reproduction of your Kudoboard and prints at 12" wide which tends to work best for smaller sized boards (<25 posts).
This poster download prints at 24" wide which tends to work best for medium sized boards (25-100 posts).
This poster download prints at 48" wide which tends to work best for larger sized boards (101+ posts).
These widths generate a 200 DPI print, which tends to work well for posters. You can adjust, but note that blowing it up will decrease image quality.