Serious knife folks, collectors and makers, know the differences between Wootz, Damascus, patterned-welded and folded steels. They look similar, and sometimes overlap in how they are made, but there are differences.
Originally, the pattern-welded and folded steels came about because the metals were sometimes poor, and one can increase the strength and edge-holding abilities of a blade by blending and making a steel that is more than the sum of its parts.
You get a hard section for the edge, more flexible for the body, like that. Heat it, hammer it, and forge a better tool.
A lot of cultures played with these, the Japanese, the Vikings, the Indonesians, and they all added this or that, hammering and folding and coming up with blades that worked better and looked better. The Indonesians have books that deal with the patterns of pamor, there are hundreds of them, with different meanings.
These days, with the excellent steels available, pattern-welding and Wootz and such aren’t necessary, and this kind of thing is done more for the look than the function.
I have several knives and a small collection of older kerises and kerambits with the traditional patterns, and some of them are quite striking.
Here is the latest addition to my collection, a small pocket folder with what is called “Raindrop Damascus.” Gorgeous …