Photo engraving with a laser or mechanical machine
How to do photo engraving on different materials with precision? Laser or mechanical? Our experts have the answers!
Photo engraving (human or animal portraits) have been a strong trend for several years now. Today, it can easily be achieved with mechanical or laser photo engraving machines, a durable alternative to conventional printing.
From jewellery (pendants, bracelets, etc.) to personalised gifts and funeral plaques, this technique enables images to be engraved permanently on a variety of materials (glass, wood, acrylic, stone, etc.). Photos can also be vectorised for a drawing effect, opening up even more creative possibilities.
What you need to know about photo engraving
Format & Resolution
The right format
To obtain high-quality engraving, you need to pay close attention to the file format used: .png, .jpeg, .jpg, tif or .tiff.
Please note that photo engraving is not compatible with proprietary formats such as .raw.
The right resolution
A photo must be of the right quality to be correctly interpreted by the software and adapted to the required format.
The larger the image, the higher the definition must be. So, if you want a precise rendering for your photo engraving, opt for a good resolution (minimum at 300 DPI ). A poor-quality, overly pixelated file is likely to give a blurred or poorly detailed result, as the photo engraving machine will not be able to reproduce high definition.
However, engraving parameters (including resolution) will influence engraving time.
Contrast & Background
The right contrast
Photo engraving has no color, it's based on levels of grey. An overexposed or underexposed photo will produce a "flat" effect. It is recommended to retouch the photo on external software (such as Adobe Photoshop, Gimp, Canva), in particular by sharpening for a better effect.
Negative etching
For some materials, such as acrylic, glass or anodised aluminium, engraving will lighten the material. You should therefore engrave in negative (light areas on a dark background) for the best photo engraving results.
Good triming
To improve the result of your photo engraving, you can remove unnecessary backgrounds with tools such as Remove.bg.
Photo laser engraving
Materials
The materials on which photos can be engraved depend on the source used in the laser photo engraving machines.
CO2 lasers are ideal for engraving:
- Organic (wood, glass...);
- Plastics (acrylics...);
- and painted surfaces (anodised aluminium...).
Fiber/Green/Hybrid lasers, on the other hand, are more commonly used for photo engraving on metals and precious metals, for precise, long-lasting engraving: steel, gold, silver...
Greyscale or dot density?
Photo laser engraving works like a printer, creating more or less pronounced pixels, either in greyscale or in dot density, depending on the material.
With some materials, such as anodised aluminium, wood or glass, it is not possible to work in greyscale you must therefore use dot density mode (or raster mode).
You also need to pay close attention to the expected rendering:
- for precise photo laser engravings, the dot screen (the size of the dots) varies according to the greyscale, for an aesthetic rendering;
- for larger applications (wall decorations or trophies), dot density (or halftone mode) is preferred.
Grey level diagram | Dot density diagram |
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Suitable laser photo engraving machines
The choice of photo engraving machine depends on the rendering and format required.
- The WeLase™ machine is ideal for fast, precise unit photo engraving on small formats.
- The LS100, LS100 EX or LS900 machines are ideal for larger-scale or mass production engraving, particularly for funerary purposes, on bottles or cylindrical glass objects (thanks to the rotary device).
Our engraving material Gravoxal™ is the ideal material for photo laser engraving. The laser's precision and the high-quality anodisation ensure the best result for photo engraving, delivering optimum monochrome shading.
The parameters to be used in the Gravostyle™ software for photo laser engraving
For optimum rendering, you can configure your engraving parameters in Gravostyle™:
- select the DPI (up to 300 DPI for wood and up to 1,200 DPI for anodised aluminium to avoid the risk of overlapping dots);
- select the focal lens (for small photo engravings, a 1.5 mm lens is recommended; for larger formats, a 2 mm lens is more suitable to lower resolution and save engraving time);
- use a negative mode (depending on the material to be engraved);
- choose material presets (speed and power depending on the material, predefined settings in Gravostyle™)...
Please note: for acrylic, remember also to set the mirror mode for the best results.
Mechanical photo engraving
Dot density in mechanical photo engraving
Metal is the key material for mechanical photo engraving. The rendering on this material is all the more qualitative when you play with light and with the rotation of the product.
In mechanical photo engraving, photos are reproduced by a system of dots, as greyscale rendering is not possible with this technique.
To obtain a quality image, the density of the dots is adjusted, increasing the resolution and precision of the engraved motif.
The ideal mechanical photo engraving machine:
the M20 X
The M20 X with diamond offers a handcrafted finish for photo engraving, perfect for jewellery items or gifts such as key-rings.
Thanks to Gravostyle™ software, and the option of Photostyle with mechanical photo engraving machines such as the M20 X, a photo is converted into a set of adjustable dots, optimising visual rendering on metal substrates.
This method guarantees a neat, detailed result, ideal for high-quality photo engraving.
Focus on fingerprint engraving
Fingerprints can be engraved using mechanical or laser photo engraving machines.
- Laser engraving - A black-and-white photo of the fingerprint (obtained via a fingerprint reader or by scanning) is directly engraved. The precision of the laser photo engraving machine enables us to reproduce the finest details of the fingerprint's texture.
- Mechanical engraving - The photo of the impression is vectorised and transformed into a contour file, which the photo engraving machine then follows to engrave the lines of the impression with precision.
Photo engraving, whether laser or mechanical, requires a minimum of technical expertise. Before taking the plunge, remember to carry out several tests to guarantee optimum results. And for more information, don't hesitate to contact our experts!