This is how you etch.
You take a sheet of metal. You cover it in wax. You take a needle and use it to scrape your design into the wax. You may wish you use an echoppé. I don't care. Now - and this is the important part - you dip the whole thing into acid: strong, metal-devouring acid. This acid is called the mordant or etchant. Mordant from the Latin mordere meaning to bite, etchant from the German ätzen, from Old German azzon meaning to bite.
This is the point: the biting. The acid bites the metal and dissolves it.
Then you remove the wax, put some ink on the metal and use it to make a print.
This is not the same as engraving. This is not the same as carving. This is not the same as tattooing. This is using damned acid to burn up metal. Got that?
Given this, I shuddered when I discovered that a lady/river called Jordan had had her husband's name "etched on her wrist". I hope they meant tattooed. There is, of course, such a thing as metaphorical language, but if you can explicate how David Beckham's face was "etched in agony", as The Times reported, you are cleverer than I am.
Faces get etched a lot. Yesterday's Observer reported that "Years of conflict" had been "etched on a Congo village chief's face", which is a crime either against humanity or English usage. Written would have done. Or simply "Chap in difficult circumstances looks a bit glum". There was nothing extraordinary about his face. I know because they had a picture of it. I would have said he's looking pretty good for a seventy year old: quite a bit better than Shakespeare looked at that age.
The BBC, reporting on "etched" paleolithic ostrich eggs, either has no idea what etching is or has placed the discovery of metals and acid 59,000 years earlier than was thought. But give a journalist a verb and they'll probably change it to etch. For example: "President Obama's landmark healthcare bill narrowly etched itself into the US House of Representatives, etching in the most etching health reform in decades."
They are engraved. Carved. Scratched. Scraped. They are not bloody etched. If you ain't using acid, you ain't etching.
Incidentally, and only because it's a couple of words down in the dictionary, when children are trying to get their parents' attention they're being etepimeletic.