Join Date: Nov 2005
I think the pattern difference above is a lighting artifact, with different lighting the pattern should look uniform across the surface.
Patterns in wootz come from the fact that when the steel starts to solidify, the first crystals 'want' to be pure iron/carbon - the impurities in the melt become concentrated in the areas of secondary crystalization, in between the networks of already solid metal. So the impurites do get localized to a degree.
Theoretically, you can control the grain orientation, and hence ultimate pattern, by manipulating the shape of the solidifying metal (by casting into a mold of varying thickness), but I don't think anyone is working on this yet.