Tips and tricks for photo laser engraving

Photo engraving using JobControl® laser software is made easy by using its integrated photo mode feature. The image is automatically sent to the laser for processing in an optimised manner according to a complex logic. Using this feature, you can create high-quality photo laser engravings and the best part is that no photo processing expertise is needed. 

One of the major driving factors of what makes a photo suitable for laser engraving is the resolution. Images for laser engraving should generally have a resolution of at least 300dpi as the output size. If necessary, you can increase the resolution in your graphics software by re-establishing the bitmap (example in CorelDraw under “Bitmaps” - “Resample”). For example, Internet photos often have a resolution of 72 dpi. Even these can be processed well with the laser, if the original images are large and are scaled down to workpiece size. You should avoid enlarging small images, as this decreases the resolution, that is, the image raster becomes too large and is therefore not a basis for a beautiful photo engraving.

Here are two examples of well suited versus ill-suited images for photo engraving:

The left image is well-suited for processing with the laser. It shows a good contrast, it is well exposed and the elements in the image stand out.
The right image is less suited for processing with the laser. The people stand out from the background, but the exposure is too weak, which makes the people look like they are in the shadows. This makes it difficult for details to be perceived, and the people would be engraved as a unitary surface.

Often, the laser performance and the resolution used are too high, and the image becomes too flat and shows little detail, as the raster points overlap. If possible, the material should only be engraved slightly at the surface. A guideline is about 10% less laser performance compared to a standard engraving job on this material.

TIP: In order to find the perfect parameters for your material, you can first engrave a grayscale matrix.

More about grayscale matrix

The process resolution is an essential influence factor for the engraving quality of different materials.
For example, anodised aluminum can be engraved with 600 - 1000 dpi, as the raster point does not increase on this material during engraving. With wood or glass however, 333 dpi are completely sufficient, as every raster point becomes larger than in the graphics on these materials due to their surface quality. With acrylics or laminates, a resolution of about 500 - 600 dpi is suitable.
In general, lower resolutions (333 -500 dpi) result in more plastic photo engravings, because the raster points do not overlap.

A 1.5“ lens is often the best choice. The exceptions are workpieces with a large engraving area, or those that are viewed from a greater distance. In this case, use a 2“ or 2.5” lens, and select a lower process resolution. This also saves time.

You will get the best results with a photo engraving using images that have high contrasts. It is important to remember that not all photos are the same, and not all materials are the same. Sometimes you may have to process the images to make them more suitable for laser engraving. For example, you can increase the details of your photos with contrast improvements or the unsharp mask. Most graphics programs have these functions.