James Michener's The Novel is about a writer who is also devoted to art, and especially to the rescue of old Pennsylvania Dutch barn designs. No doubt it was the impetus for a revival of interest in the "barn flowers" as the hexagonal signs used for outdoor decoration were sometimes called. Although a number of fakelore artists of today are busily attributing magical properties to the art of this genre, hexagonal simply means six-sided, ergo the name "hex signs." Can you picture a farmer using a pitchfork to help measure out the patterns?
Speaking of barns, this link has some nice barn photos, including that of a delightful star barn: Star Barn
This brings to mind that the barn flowers were also called barn stars. Well, I could not resist making some fakelore of my own:
I did not have a pitchfork, so I kept the figure six-sided. That way nobody can say it is not a hex sign :-)


