What is the difference between chemical etching and engraving?

Chemical etching works by creating a mask layer containing the artwork on the surface of the material and spraying the exposed areas with a high-pressure acid spray. The mask layer can be created in many ways, ranging from a laser engravable etch resist, UV photosensitive film, vinyl, and digital printing. The material is dissolved atom by atom, producing a smooth burr-free finish and leaving the material grain structure unaffected. There is no heat distortion as associated with laser processing, and no tool wear similar to what occurs when processing hard metals, such as stainless steel, by mechanical engraving methods.

The main advantage of chemical etching is that it etches the whole surface area of the material at the same time. A laser has to mark each area individually, often making many passes to achieve tangible depth. With chemical etching, the amount of detail and size of the etch area have little effect on the process time. This means that it’s possible to deep etch even large and complex designs in minutes. It’s also possible to etch away the bulk of the background to create raised texts and images in a way that might be difficult or time consuming with mechanical engraving methods.