If I have to be honest - I dont have a clue either. Strange how many people know what the technique means, but very few know how it is done.
Have a look here.
http://www.gemologyonline.com/Forum/...pic.php?t=1754
I just saw this.
http://blog.mirraw.com/2012/09/18/wh...undan-jewelry/
So there seem to be different oppinions of how it was done.