A handkerchief is not the same thing as a pocket square. Everyone makes this error; it makes us lose our patience. A handkerchief is a matter of hygiene. A pocket square is an accessory. You'll want both, and both the silk and cotton kind, for cleaning and bandaging wounds. Of the two, a pocket square is probably more essential in a zombie apocalypse, because it completes the outfit and zombies will know you're a gentleman. In a zombie apocalypse, no one is going to want to borrow your handkerchief, trust us. A box of 13 Jos. A. Bank cotton handkerchiefs is $42. Solid silk pocket squares start at $18.
Barbara Haddock Taylor, The Baltimore Sun