It seems so simple: draw what you'd like on porcelain with a Sharpie, bake it, and enjoy it! The website I got this from even said I could run it through the dish washer.
I decided to give the project the benefit of the doubt. Maybe it was just excess Sharpie that I had smudged off. And I wasn't about to put it in the dish washer, in case it needed a more gentle cleaning.
The plus side is that, since it was so easy for the pattern to wash off, all I needed was a sponge to get the rest off. At the end of the day, I do now have a beautiful new water pitcher for my plant and my cat's water bowl. I guess it'll just have to be design-free.