The usage of Kao on gendaito

[m4l700]

Maybe a strange question, but something I was wondering about for quite some time now and I couldn't really find any good information about this subject in the books, internet and here at nmb. Perhaps someone here know the 'true' meaning?

 

Why did some (RJT)smiths use their personal seal on certain blades? And no kao on other blades they crafted? I know this usage goes back centuries, however, what is the reason to put a personal seal on a gendaito blade that they created? In my mind it would be something to use when I would be proud on the specific crafted blade, a finished product to cherish. Basically a 'personal seal of approval'. Did I just answer my own question?

 

I could be totally wrong here, but I wonder if there just is a logical reason behind it?

 

[Bruce Pennington]

It’s an old practice, from way back. I have never read an explanation on who started it or why. Around here, though, the man who asked the question gets assigned the research! Let us know what you find out! Ha!

 

Edit:  After re-reading your post, I realize I misunderstood your question.  I remember it being discussed years ago, and while no one knew, the predominant theory was the same as yours.  It would take some research into blades made by smiths who used kao to see if non-traditionally made blades got the kao or not.

[DoTanuki yokai]

I think the blades crafted for the military must fulfill specific conditions and how the mei has to look was also given.

But im no expert and the smiths had some freedom in many things.