For those who might like to use more moss in their messaging:

This DIY tutorial comes from a book called More Show Me How and you can view larger, clearer graphic and step-by-step instructions from the book here on Popular Mechanics.  One of eight selections from the book, you can also learn how to make a metal detector, a backyard raku kiln, and a pretty labor-intensive, maybe safe and effective bed warmed by hot coals in the wilderness.

Thanks to Street Art in Germany for posting this on Facebook, and Nils Klinkenberg for passing it on.