is this the reason for all the crappy iron coloured tsuba on fleabay?

[lonely panet]

Natural ``white glue wood concentrated tannic acid'' sword props (tsuba, iron props) Nanbu ironware, iron kettles, antique ironware, anti-rust agent for coloring red rust to black rust (tannin iron) | Jauce Shopping Service | Yahoo Japan Auctions. eBay Japan

[Steves87]

Maybe.... I'd wonder if the black pigment leaches once submerged in warm liquid? 

There are some well known ebay sellers who's Tsuba have this finish look. I know that once submerged, the colour from these seller's guards, does leach away, too.

I imagine that solution is far too concentrated for direct use. There are other natural methods to get very mild tannic acid solutions for use after cleaning, and I have seen posts from FH on this forum which mention these.

Also, I think Dale has also posted this link in the gun bluing thread

Edited July 30, 2023 by Steves87
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[Spartancrest]

Yes Hamfish the same sort of "instant ageing solution" is in this thread - https://www.militaria.co.za/nmb/topic/45720-fake-armourers-tsubas-in-Japan/  about half way down the page  - see Simons post Posted Wednesday at 12:11 AM