[math-fun] patterns in steel, damascus steel, interesting patterns

Hello, I just contacted an old friend who lives in France and specialize in the fabrication of knives and 'eggs of Damascus', the interesting thing is that when they make those egss, patterns appears on the surface which are intriguing. http://damascus.free.fr/f_damas/quest.htm and see the eggs here : http://oeufs-damas.com/index.php http://oeufs-damas.com/oeufs/oeuf_08.jpg They are considered decorative and they sell it. (I am not trying to sell those things, just pointing to an interesting phenomena). Simon Plouffe