The most common sizes for graphic recording are 40" x 60" or 4' x 8'. Flip chart sized paper or boards work better in some cases, though. Regardless the size, everyone benefits the most when the graphic recording is done where everyone can see. And displayed where folks can talk about the content after the fact.
One Squiggly Line Blog
Hand-drawn pictures can make things clear, simple, and fun in blogs, too!