NU-Gold made black by vinegar?

Hello there. I’ve got this nice piece of detailing done in
nu-gold/merlin’s gold because I recalled some dim memory of someone
once saying I can make it a nice black by applying vinegar when it’s
heated. I just tried it, no such luck. Better results with l.o.s… Am
I not adding the right things or is this a poor memory?
My thanks, -A

Hello Angela

Try getting some gun black available at most gun stores. It is used
on brass and copper on guns and knives and is not expensive. As long
as you seal the container tightly between uses it will last for
years.

Karen Bahr
Karen’s Artworx