By "Clara's Trendy Designs" Had a large black slate begging to be engraved. Note: The image was also dithered to be engrave on wood. See How-to engrave wood with same image.
Photo is of horse. The Horse was made by an artist using Paper Mache like strips that were rolled and shaped and assembled. The photo is high contrast and dithers for multiple materials perfectly.
In ImagrR it was sized, DPI 282, and dithered for black painted tile material.
Advanced Settings color change had the settings that appear applied.
Advance Settings #1 had Automatic Sharpen setting 6 applied.
Material: Marcin, white tile painted black. Inverted box checked.
In XCS Focus laser, set marking area and set the settings:
Power: 50%
Speed: 100 mms
Line/cm: 280
Bitmap mode: Atkinson