Hi,
I just want to make this clear, not only japaneese did that folding, but europeans as well. Now I'm not some grungy wannabe swordspecialist, but this much I've learned from different sources, that folding in japan is not some magic stuff which was thoght out to create some überstark weapon of war, but simply because japan had one of the worst quality of iron and carbon available and that it was a must to fold it. That does not mean, that Europe and the Balkans, not to mention India and China, did not have quite a dozen different methods of weapon smithing, from laminated or folded metal to damascene. The Japaneese sword being in any form superior to any other sword in the world, is just part of the Martial Arts Mythology Collecton, available at you local McDojó. This japaneese swordmaking thechnique is horribly abbreviated.
The second myth, that the soft metal in a laminated sword is meant to absorb while the hard metal is meant to be hard and cut has also been many times proven absolutelly wrong. Check this out:
http://www.tf.uni-kiel.de/matwis/amat/def_en/kap_5/advanced/t5_1_1.html
Carbon transferes from the harder to the softer metal in the creating process, making quite a homogeneous quality of metal, while looking of course extremelly good. No real swordsmith would want to create a blade (which is meant to take heavy punishment and has lotsa jobs to do) which has, in any sense, materials with different caracteristics (just imagine, what happenes, if the enemy hits the blade in the wrong place? What if the folding was not mm exact and some layers are smaller, wider, flatter or whatever than the same ones on the other side of the blade?)
Fact is, many swordsmiths from the middle ages would have fallen unconcious if they saw how homogeneous the carbon steel is, that anybody can buy today at the local metallshop; and that you are able tu buy extremelly good carbon steel instead of low-carbon iron, with which you have to work yet for another week before you can even begin thinking about a sword.
Yet above all this, there are only very-very few swordsmiths today who actually can produce anything near as good as a true medieval blade.
Byez,
Szabolcs