Engraving Techniques

Engraving Techniques

There are several ways in which data can be inscribed onto a tag, plaque, plate, or indeed any object that is suitable. The technique used is relative to the material to be engraved, as well as the intended purpose of the engraved item.

It is therefore important to first know what the engraved object is going to be used for. Once we know this, we can advise on appropriate substrates (materials) that are best-suited for the intended application.

Router Engraving
We generally use router-engraving, which is a mechanical process involving either a carbide router cutter, or a diamond-tipped engraving tool. Both tools will scratch or "carve" the characters into the substrate. With diamond engraving, this "scratch" is actually quite deep, and leaves a permanent mark on the material. It is generally not suitable for plastics, acrylics, wood, slate or ceramics, but is widely used to engrave metal objects - from fine jewellery to industrial identity tags.

Carbide routers are used to engrave most plastics, wood, slate and stone, but are also used on metal, where a deep cut is required - usually to enable the cut to be infilled with a colour (epoxy or acrylic paint).

Laser Engraving
There are different types of laser engravers, and depending on the material to be engraved, the machine used needs to have the technical capability of rendering a mark on that material.

The most common laser engravers are  described as "CO2". The beam intensity is relatively low, and the process is assisted using carbon-dioxide (CO2). This limits the laser's capacity to mark metals, so CO2 lasers are best used for plastics (that don't contain chlorine), wood, leather, card, paper, etc. Metals (excluding anodised aluminium)need to be prepped with an emulsion before being marked. The emulsion is photo-sensitive, and the laser will darken it, leaving the engraved mark. This is a superficial mark, so is susceptible to wearing off and fading. We do not recommend this method where metals are to be engraved.

Increasingly common are Fibre-laser machines which have a high-intensity beam, capable of annealing metals. Annealing is a heat process, where the heat source discolours the metal. Some high-powered fibre lasers can also cut through metals. There are many "versions" of fibre lasers, with different beam intensities and engraving/cutting capacities. They are not commonly used by smaller engraving businesses because they are very expensive - and the more sophisticated fibre laser machines can cost over £100,000 .

Hobbyists often use small diode laser engravers which are cheap, but have low power and are generally unable to engrave to the precision needed for commercial applications. For simple projects, these machines are OK, but few commercial engraving companies would use them.

CNC machines
Today, almost everyone involved in the engraving industry will use CNC techniques, where the action of the engraving machine is controlled through software. Whether router or laser, CNC principles will govern how an item is engraved. Precision, accuracy and quality is therefore determined by the sophistication of the software, as well as the machine doing the actual engraving. It's obvious therefore, that a cheap machine using simple software will not deliver high-quality results.

Pantograph Engraving Machines
This technique is seldom used for commercial engraving today, but some people still have a pantograph set-up and use it for specific projects. Essentially, the technique uses sets of debossed dies in all alpha-numeric characters. These dies are wedged in a holder, and - using a pantograph process - the engraving is applied by a hand-operated process of following each die, with the movement being transferred via the pantograph arms and levers. The system was rendered redundant when CNC engraving became possible.

Hand Engraving
Sadly, these days there are very few skilled artisans who engrave by hand. This is a skill that takes years to perfect, and because it is both difficult and time-consuming, is not cost-effective. But people who do this work are still sought-after where something really special needs that personal touch. It is a dying art and this is very sad. We have huge respect and admiration for these people, but modern technology has influenced this industry and good machines are now capable of doing practically everything just as well.