Chemical etching (or chemical milling, acid etching or photo etching as its sometimes known) is a process of engraving using a corrosive chemical, called an etchant. Different materials require different etchants, however we specialise in ferric chloride etching, which is the ideal etchant for materials such as stainless steel, brass, bronze and copper.
An in depth process guide can be found below, however put simply, the etchant is sprayed at the plates, which have been protected leaving only the areas needing to be engraved exposed. The etchant corrodes the substrate in the relevant areas, leaving a deep crisp engraving.
Chemical etching is a process that has been used for hundreds of years, however despite it's age it still offers significant advantages over other techniques.
Firstly, chemical etching can achieved very fine detail and engraving of extreme complexity that wouldn't be possible with CNC engraving or manual engraving. This is because there of no restrictions on drill bit size. The process can achieve very fine points and extremely smooth curves, seamlessly.
Secondly, the base of the engraving is perfectly flat and free from any marks that you might associate the mechanical methods. This leaves the plate with a crisp, professional finish without any distractions.
As chemical etching is a process that mills deep into the substrate, it leaves an extremely resilient and hardwearing mark, significantly more so than the screen printed or laser marked alternatives. These are only surface marks which can be removed through scratches and causal abrasion.
Finally chemical etching is an extremely efficient process as many hundreds of plates can be etched simultaneously, unlike any other method. This enables has to offer very competitive rates and lead-times on high volume bespoke nameplate requirements.
The achievable depth varies from design to design, however given no restrictions or limitations it is possible to achieve an etch in stainless steel of up to 1mm. However for most plates this depth wouldn't be possible without suffering significant loss of clarity.
As the etch becomes deeper, the sides of the letters become exposed to the etchant as well as the overall shape. This leads to the letters bleeding outwards and inwards simultaneously, becoming bolder whilst still progressively gaining depth. This becomes most
apparent on letters such as e's or a's where the middle portion of the letters would be the first to disappear.
For most plates with average sized text, typical depths would be in the region of 0.3-0.5mm, whilst for smaller typefaces it might only be possible to achieve a depth of 0.15mm. Nevertheless, this is still a significant engraving and is extremely durable and is more than a match for any other equivalently process.