How to Prepare Your File for Laser Engraving

Basics

You may achieve your desired results with Affinity Photo, Adobe Photoshop, or another raster image editor. This guide is written for Affinity Photo.

The preparation process for raster engraving includes:

  • Conversion to Grayscale
  • Brightness
  • Exposure
  • Contrast
  • Sharpen
  • Dithering

Color Depth

Visual representation of grayscale depth engraving

Below you can see an example of a color image that has been converted to grayscale.

Next, we take that image and engrave at 300 DPI | 100 Power | 60 Speed | Stucki Dithering.

Grayscale

Engrave depth range is important for a user to understand. Please note the depth range of a project is separate from suggested material settings. Suggested material settings relate to the material used; however, the depth range indicates detail from how many layers your final project requires.

  • 1-BIT images are at their simplest where the laser is either on (1) or off (0).
  • 2-BIT power settings are 0-3, where 0 will not cut, 3 being the deepest cut, and 1-2 are additional layers for the project to express detail.
  • 4 through 10-BIT depths are pictured below.

  • More Black = deepest engrave
  • Gray Tones = medium engrave based on channel depth and depending on grayscale bit level: 1,2,4,8,10 bit
  • White = does not touch/engrave

Dithering

Dithering your file can result in a better overall image. This depends on material, settings, and file detail. Dithering may be done via photo editing software such as Affinity or Photoshop. The Epilog Dashboard also has dither patterns that can be selected when sending your file. A dither is not required for all engrave projects. As with most laser cutting, we recommend testing your file prior to doing a final pass.

Floyd-Steinberg

Stucki

Jarvis

Useful for engraving photos with more color depth than basic grayscaleEngraving photographs of 300 DPI; this type produces a good pattern on most photosEngraving photos at 300 DPI, similar to "Stucki"

Step-by-step guide

Preparation

You configure Engrave Depth through Grayscale. The settings below determine the depth and quality of your engraving. Keep in mind that darker tones will engrave deeper than lighter tones. For all image adjustments, you have the option to use presets or adjust via the sliders.

Setup

  1. Remove everything that you wouldn't want showing up on your final project.
  2. In my example I cropped the doorway and building name, removed the window squares from our doors and corrected the skew of my canvas.
Adjustments
  1. The location for adjustments is found on the right toolbar in Affinity, click the tab next to "Layers" titled "Adjustment"
  2. If you do not see adjustments on your right sidebar then you may need to enable them by clicking "view" on the top menu bar >> click "studio" drop down menu >> and check "adjustments".
  3. While here I'd like to point out that through Affinity all your adjustments show as a new layer and have the option to toggle on/off as would any other layers. This is found via your "layers" tool bar

Exposure

Recommended to tune your exposure through the slider.

  1. We are looking for a final image that is slightly washed-out with sharp contrast, but not overly so
    1. For this example, "+2 Stops" is washed out and "-2 Stops" is underexposed
    2. Using the sliders to adjust your exposure appropriately is recommended


Black & White

  1. When converting an image from full color I have found the sliders to be best here, using presets to find a close match and then using slight adjustments to tune your image.
  2. Sliders tune the saturation/intensity of the colors in your image in relation to grayscale. (RGB & CYMK sliders)

Brightness / Contrast

  1. As far as Brightness / Contract go I have found that the presets for this option are best, however minor adjustments may be done through the sliders for fine tuning.

Channel Mixer (Optional)

  1. This option has been useful in correcting black intensity.
  2. Here I have the output channel set to "gray" meaning I have grayscale sliders.

Inverting your image (Optional)

  1. Depending on your project, Inverting an images colors will result in a better final project. Inverting an image will result in an inverted project, meaning for the example image below, the doors are darker than the frame and as such, the doors will be engraved deeper in our material.
  2. This adjustment may be most useful in 1-bit Black & White files where the laser is either on or off,


FInal

  1. Export your file and test your material and settings.