Kiwi is great on veg-tan leather. The case you have that I made, I would recommend Kiwi Cordovan or Kiwi Neutral for it. But on black veg-tan I have had terrible luck with Kiwi, it seems to pull the black color out of the leather every time I have used it.
It can indeed leach the color out...depending on the leather.
Generally I recommend putting color in and then polish on top, if needed....
There are many reasons I am not a fan of veg tan. Obviously it is necessary for tooling leather, but I am not a tooling fan.
My favorite is simple black oil tan. Color all the way through and wears like iron. Hard to cut, hard to form...tough stuff...but that's the reason the best motorcycle boots are made of it.
I may sit and work on this tomorrow. Gentle cleaning, taking time....it's suede. The shiny parts need cleaned and the nap raised up again with a brush, it's just matted down, not worn off.
If it goes South on me I'll do it in a smooth black polish. Sacrilege to suede fans but it does work, I have done it before.
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