ISO/TR 16060:2003 gives a non-exhaustive list of etchants that can be used for the macroscopic and microscopic examination of welds in accordance with ISO 17639 for the following groups of materials:

• carbon steels and low-alloy steels;
• stainless steels;
• nickel and nickel alloys;
• titanium and titanium alloys;
• copper and copper alloys;
• aluminium and aluminium alloys.