Depth Engraving¶
Depth engraving creates 3D relief effects by varying laser power based on image brightness. It's used for creating dimensional artwork, terrain maps, lithophanes, and embossed designs.
Overview¶
Depth engraving operations:
- Vary laser power to create different engraving depths
- Work from grayscale images or height maps
- Create 3D relief effects on wood, acrylic, and coated materials
- Support multiple passes for deeper carving
- Produce tactile, three-dimensional results
When to Use Depth Engraving¶
Use depth engraving for:
- Creating 3D portraits and artwork
- Terrain and topographic maps
- Lithophanes (light-transmitting 3D images)
- Embossed logos and designs
- Textured surfaces and patterns
- Mold masters for casting
Don't use depth for:
- L Simple flat engraving (use Raster instead)
- L Cutting through material (use Contour)
- L Text and line art (better with raster)
How Depth Engraving Works¶
Power-to-Depth Relationship¶
The laser engraves deeper with higher power:
- Low power (lighter pixels) Shallow engraving
- Medium power (medium pixels) Medium depth
- High power (dark pixels) Deep engraving
Image brightness to depth:
White pixel 0% power No engraving
Light gray 25% power Light engraving
Medium gray 50% power Medium depth
Dark gray 75% power Deep engraving
Black pixel 100% power Maximum depth
Scanning Pattern¶
Like raster engraving, depth uses scanning lines:
- Back-and-forth horizontal passes
- Power varies along each line based on image
- Creates smooth gradients and transitions
Creating a Depth Operation¶
Step 1: Prepare Image¶
- Convert to grayscale - Remove all color
- Adjust levels - Increase contrast for more dramatic depth
- Invert if needed - White=high, Black=low (or vice versa)
- Resize - Match your desired output size
Image tips:
- Higher contrast = more dramatic depth changes
- Smooth gradients = smooth 3D surfaces
- Sharp edges = steep depth transitions
Step 2: Import and Add Operation¶
- Import your grayscale image
- Select the image
- Menu: Operations Add Depth Engraving
- Shortcut: Ctrl+Shift+D
Step 3: Configure Settings¶
Key Settings¶
Power Range¶
Minimum Power (%):
- Laser power for lightest areas (white pixels)
- Usually 0-20%
- Set higher to avoid very shallow areas
Maximum Power (%):
- Laser power for darkest areas (black pixels)
- Usually 40-80% depending on material
- Lower = subtle relief, higher = dramatic depth
Power Range Examples:
Min | Max | Effect |
---|---|---|
0% | 40% | Subtle, light relief |
10% | 60% | Medium depth, safe |
20% | 80% | Deep, dramatic relief |
Start conservative:
- Test with 10-50% range
- Increase max power for more depth
- Increase min power to avoid unengraved areas
Speed¶
Speed (mm/min):
- How fast the laser scans
- Slower = deeper engraving at same power
- Typical: 1500-3000 mm/min
Speed vs Depth:
- Half the speed = roughly double the depth
- Very slow speeds can char or burn
- Test to find optimal speed for material
Line Interval¶
Line Interval (mm):
- Spacing between scan lines
- Smaller = smoother 3D surface
- Typical: 0.05-0.15mm
For depth engraving:
- Use finer intervals than normal raster (0.05-0.08mm)
- Smooth 3D surfaces need close line spacing
- Visible lines create ribbed texture
Multiple Passes¶
Passes:
- Number of times to repeat the engraving
- Each pass adds more depth
- Typical: 1-3 passes
Why multiple passes?
- Safer (less risk of burning)
- Deeper total depth
- More consistent results
- Better for hard materials
Single pass vs multiple:
- 1 pass at 80% power
- OR 2 passes at 50% power Usually better
Invert¶
Invert Image:
- Enabled: White = deep, Black = shallow
- L Disabled: Black = deep, White = shallow (default)
Use invert for:
- Lithophanes (light areas should be thin)
- Embossing (raised areas)
- Inverted height maps
Material Considerations¶
Best Materials¶
Excellent for depth:
- Wood - Natural, forgiving, good depth range
- Acrylic - Clean results, good for lithophanes
- Leather - Creates beautiful embossed effects
- Coated materials - Removes coating in varying depths
Challenging:
- Metals - Require marking compounds
- Glass - Difficult without special coatings
- Very hard plastics - May require high power
Material-Specific Tips¶
Wood:
- Start with 10-50% power range
- Softwoods engrave deeper than hardwoods
- Watch for grain direction affecting depth
- Multiple light passes better than single heavy pass
Acrylic (for lithophanes):
- Use 3-6mm thick clear acrylic
- Engrave from back, light shines through front
- Thinner = more light, thicker = darker
- Power controls remaining thickness
- Invert image (white = thin, black = thick)
Leather:
- Very forgiving material
- 15-40% power range typical
- Creates beautiful embossed look
- Test on scrap (each leather type differs)
Tips & Best Practices¶
Image Preparation¶
For best results:
- Use high-resolution images (300+ DPI)
- Increase contrast before engraving
- Blur sharp edges for smooth transitions
- Remove noise (creates unwanted texture)
- Test on small area first
Adjusting images:
- Too flat Increase contrast
- Too much depth Decrease contrast
- Rough surface Apply slight blur
- Missing detail Sharpen slightly
Testing Strategy¶
- Small test square - 20mm 20mm area
- Power range test - Try 10-40%, then adjust
- Speed test - Try 2000-3000 mm/min
- Line interval test - 0.05mm vs 0.1mm
- Scale up - Use successful settings for full image
Quality Settings¶
For highest quality:
- Line interval: 0.05-0.08mm
- Multiple passes (2-3) at lower power
- Slower speed (1500-2000 mm/min)
- Disable bidirectional scanning
- Material must be perfectly flat
For faster results:
- Line interval: 0.1-0.15mm
- Single pass at higher power
- Faster speed (3000-4000 mm/min)
- Enable bidirectional scanning
Common Issues¶
Uneven depth:
- Material not flat secure better
- Focus incorrect adjust focus
- Power unstable check laser
Too shallow:
- Increase max power
- Decrease speed
- Add more passes
- Use softer material
Burning or charring:
- Decrease max power
- Increase speed
- Use more passes at lower power
- Improve ventilation
Ribbed/lined surface:
- Decrease line interval
- Check that material is flat
- Try different scan angle
Advanced Techniques¶
Lithophanes¶
Lithophanes are 3D images viewed by backlighting:
Process:
- Use clear acrylic (3-6mm thick)
- Engrave from back side
- Invert the image (white = thin)
- Power controls remaining thickness
- View from front with backlight
Settings for lithophanes:
- Power range: 20-70%
- Line interval: 0.05mm
- Multiple passes: 2-3
- Very important: material must be flat
Terrain Maps¶
Create 3D topographic maps:
Process:
- Get height map (white = high, black = low)
- Increase contrast for dramatic relief
- Use 10-60% power range
- Fine line interval (0.05-0.08mm)
Combining with Contour¶
Add depth engraving inside a contour cut:
Workflow:
- Depth engrave the image
- Contour cut around the perimeter
- Result: 3D relief plaque that's cut free
See Multi-Layer Workflow for details.
Troubleshooting¶
Image looks flat, no depth¶
- Increase: Max power setting
- Increase: Contrast in source image
- Try: More passes
- Check: Material is suitable for depth
Surface is rough or textured¶
- Decrease: Line interval (try 0.05mm)
- Apply: Blur to source image
- Reduce: Power (over-burning creates rough texture)
- Try: Different scan angle
Inconsistent depth across image¶
- Check: Material is flat and secured
- Check: Focus is consistent across area
- Verify: Laser power is stable
- Try: Smaller area (check if issue persists)
Burning at dark areas¶
- Decrease: Max power
- Increase: Speed
- Use: Multiple passes instead of one
- Improve: Ventilation/air assist
Image is backwards¶
- Flip: Source image horizontally
- Or: Engrave from opposite side
- Check: If creating lithophane, engrave from back
Technical Details¶
Power Modulation¶
Depth engraving uses PWM (Pulse Width Modulation):
- Laser power varies continuously along scan lines
- Each pixel gets proportional power
- Smooth gradients require many power levels
Grayscale to Power Mapping¶
Linear mapping:
For inverted:
Resolution¶
Image resolution affects quality:
- 254 DPI = 10 pixels/mm use d0.1mm line interval
- 508 DPI = 20 pixels/mm use d0.05mm line interval
Higher resolution images can produce finer detail.
Related Topics¶
- Raster Engraving - Flat engraving with scanning lines
- Contour Cutting - Cutting around depth-engraved pieces
- Multi-Layer Workflow - Combining depth with other operations
- Material Test Grid - Finding optimal power/speed settings
- Overscan - Improving engraving quality