Opinions on blade manufacture
 

I am curious about the center section of this blade. It seems to be a form of twist core but it has an almost 3D topographic effect. Did the smith choose not to grind down this section of blade to give this effect or is something else going on? I have seen aggressive etches which create some topography but never this bold. You can feel the sharpness of the metal if you run your finger down the center panel.

Thanks in advance for your feedback.

This keris blade was made in Madura, probably in the Sumenep area, and probably late 19th century.

It is a typical Madurese pamor pattern, not particularly scarce in Madura keris, but can occur in keris from Jawa and other areas also.

There are a couple of ways to make this pamor, most usual is to inlay the twisted pamor material into the center of the blade billet prior to final forging. The topographic effect is created by repeated etching with mild fruit acids over time. In recent blades this etch is hastened by controlled etching to produce the topographic effect.

It is not a "twist core". Actually, I find the term "twist core" a little bit confusing, but what I believe people mean when they use this term is that a steel edge is inlaid into a billet of twisted material.

Thank you Alan for the information.