Michael’s card stock reacts to laser engraving by removing the dye and leaving a tan color behind. So I tried this as an experiment.
Grabbed a picture of a grape leaf
Took it into Photoshop. Converted to Grayscale, inverted, Find Edges, Adjusted Levels
Took that into Inkscape and traced outline with a vector. Then back in Photoshop I removed the outline so just the veins were left. (Also remove the stem because it was too small in the scale I was printing in). I replaced the raster in my Inckape file with that one.
Saved the svg with the veins as raster and the outline as vector.
Engrave the veins at 500/1 and cut the vector at 500/25