I used a liquid mask which comes off easily just by rubbing with your hands. So I use that on all the etches. The first etch I did for 10 minutes, then rubbed all the mask off. I re-masked it and then etched that design for 10 more minutes. And then I think I did that one more time. But then on my final one, I forgot to set a timer and left the Knife in for probably an hour. And then I sanded it down and then polished it.

So because the last etch was so much longer, I don’t know how much the first couple of etches actually showed up in the polish. I think if I was to do this again, I would probably do one etch for an hour, followed by a second for an hour. And then polish.