It can be quite confusing to the average person not skilled in the art of etching or engraving to truly understand the difference of the two processes. Although the results can be similar, the two processes are very different. Lets start with engraving.
Engraving is the process of mechanically removing material from the surface of an object using direct contact of a tool. This is commonly done with computer controlled machines that rapidly rotate or pulsate a hardened tool against the surface of the material to remove or compact the material leaving a pattern, or recess in the material. A common tool for this process is a mill, or an engraving machine.
Engraving is generally done when the depth is greater than what you would intend to etch to, In the Etching process, which is intended for shallower applications, a solvent resistant film, called a mask, is adhered or printed onto the material over the areas you do NOT want removed
The material is then placed into a solvent bath, which dissolves the areas exposed to the solvent. In metals, the solvent is usually a strong acid, which removes layers of the metal exposed to the solvent while leaving areas that are masked untouched. Later, the mask can be removed, and the surface exposed leaving a shallow path cut into the surface. Modern electronic boards are also made utilizing this technique. In electronics, a board made of fiberglass is coated with a layer of copper across the whole surface. The board is placed into a machine that prints an ink onto the board in the exact pattern that the electrical circuits are to be made. The ink is UV cured, then the board is washed in a bath of sulfuric acid, which removes all the exposed copper leaving only the fiberglass board underneath. You are then left with “wires” on the board exactly where they are intended for electricity to flow.
Etching is generally utilized to remove thin layers of material without changing the surrounding material density, where engraving can alter and stress the material around the area impacted by the tool. Engraving requires a machine to pass a tool over every single part of the area one wishes to alter, and can be quite time consuming and costly over large areas and large production runs.
Etching, on the other hand does not rely on having to physically alter every part of the product, but relies on a chemical process to alter the whole product at once. You can stack many parts in an etching solution and let the chemicals do the work, whereas, in engraving, you need the full attention of an engraving machines for each part. What’s the difference between etching and engraving? This article will help you to distinguish.