Christoph found this bag on a cruise, but oh no! I wonder how many of those got printed? The German word for fold, 'falten' is misspelled as 'falzen'. However, I've seen the word 'falzen' on other bags, such as Transat, so just what is proper?
Mystery solved! According to fastidious Swiss bagman Stefan Zingg, While it is true that the "generic" word for "to fold" is "falten", the word "falzen" also exists. It means "to fold" as a bookbinder would do it, carefully, using a paper-knife. So while I myself would write "falten" onto such a bag, "falzen" isn't wrong, depending how carefully you do are intended to fold it."
What's a paper knife? The best I can come up with is from the Frank Zappa song called Flakes. "I'm a moron and this is my wife, she's frosting a cake with a paper knife. All that we got here's American made, it's a little bit cheesy, but it's nicely displayed".