Copper Etchants

These are etchants recommended for copper alloys. The order of preference is from left to right.

Type of Copper:
Etchant to Use:

Pure copper
Copper etch

Cu-Ni
Acidic ferric chloride

Copper alloys, brass, bronze
Copper etch or Ferric chloride etchant

Macro-etching Copper
Ferric chloride etchant

Copper Etch
• ASTM E407 formula 30, a popular general-purpose etchant for copper, brass, and bronze. It produces a nice flat etch for some copper alloys. This product has two parts. The user has to combine them before use. Use fresh.
Acidic Ferric Chloride
• ASTM E407 formula 34. Show the general structure of copper. It’s strong and effective. Immerse or swab a few seconds at a time. Repeat as necessary. Pre-mixed, ready to use.
Ferric Chloride Etchant
• A modified, milder version of Acidic Ferric Chloride. It’s a general-purpose micro/macro etching solution for copper and brass. Produces grain contrast. Pre-mixed, ready to use.