Looking on the internet deeply has found these results:

etchant is the most popular phrase on the web.

etching solution 1359,000 results on the web	etchant 1504,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
etching solution to lift it up. A1130 Spent etching solutions containing dissolved copper I used an acid	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

etching solution

1359,000 results on the web

etchant

1504,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.