I've been on a Guilloché binge for a few weeks now and found this gem accordingly. Well worth the 80MByte download. Check this link (http://demonstrations.wolfram.com/GuillochePatterns/) for the Guilloché generator (and also can get the link to the Player). I actually exported the result as a vector via a postscript printer driver, converted the vector to an SVG file using Ghostview (PStoEdit), and enhanced the SVG file via GIMP. :)