Virtually all metals can be etched but some etch more easily than others, commonly etched metals include:-
Stainless steel
Other steels including Tool Steel, Mild Steel, Carbon Steel
Various Nickel Alloys
Copper
Inconel
Copper Alloys including Brass, Phospor Bronze, Nickle Silver
Aluminium and Aluminium Alloys (Care needs to be taken as the formation of Aluminium Oxide is Exothermic process so appropriate cooling coils need to be utilised)
Silver and Silver Alloys
Gold and Gold Alloys
