The finish they leave is very different...just something to keep in mind. I get my ferric chloride for $6 a bottle at Radio Shack and mix it 4:1 distilled water:ferric.
Vinegar leaves more of a whitish/light grey etch, while ferric is much blacker/dark grey. Here's an example of that Gold Dollar.
![$20150831_171425-01.jpg $20150831_171425-01.jpg](https://xfdata.badgerandblade.com/attachments/352/352949-cf3e1382d5c13d5a8e0b1dcddfb21ab3.jpg)
Again, not sure if that helps...but for the price its a nice result I think.
Vinegar leaves more of a whitish/light grey etch, while ferric is much blacker/dark grey. Here's an example of that Gold Dollar.
![$20150831_171425-01.jpg $20150831_171425-01.jpg](https://xfdata.badgerandblade.com/attachments/352/352949-cf3e1382d5c13d5a8e0b1dcddfb21ab3.jpg)
Again, not sure if that helps...but for the price its a nice result I think.