Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

I read online that with the carbonless copy system that the printing comes out blue. I had never paid any attention to it before, but my checkbook is a carbonless copy system. And sure enough, the printing comes out blue.

So, how could this be a carbonless copy?

And since with carbon copies there is only one white one, the original, what explains the existence of this other white one?