The rules for combining a pocket handkerchief with a bow tie are the same as those for a tie. Go ahead, so ... good taste!
A kind of silk obtained printing the design directly on a solid panel. The most complicated designs are almost always printed. The printed silks are perfect for making 7-fold ties and Untipped ones because of their light weight. Printing is divided in two categories: modern print and traditional one, still handmade. The latter is rare and much valued.