Usually you use a negative image because the parts you are etching off become white. Like these black coated aluminum cards. This makes the image appear in the correct relation of black/white.
Stain will go down to various depths, so you can’t just wipe it off with a laser pass or two…
Putting a part back into the machine and getting it lined up is next to impossible without some kind of external help, like a jig to hold it in place. It has to be very accurate if you’re going to expect it to line up.
With wood it’s unlikely that you can recover it… However it is good fodder to test out theories… You don’t need to test on the whole piece… you can pick parts…
I’ve used these a number of years and have only used cleanup passes on the fiber working with non natural products. I’d like to see how you’re using it.
Lots of people here do wood … so hang around. It’s always nice to see what you’re talking about… most of the time what we image from your words are not what we see in our minds or the photo… Photos are very helpful.
Good luck
