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Shrink Wrap

Shrink Wrap creates an efficient cutting path around multiple objects by generating a boundary that "shrinks" around them. It's useful for cutting multiple parts from a sheet with minimal waste.

Overview​

Shrink Wrap operations:

  • Create boundary paths around groups of objects
  • Minimize material waste
  • Reduce cutting time by combining paths
  • Support offset distances for clearance
  • Work with any combination of vector shapes

When to Use Shrink Wrap​

Use shrink wrap for:

  • Cutting multiple small parts from a sheet
  • Minimizing material waste
  • Creating efficient nesting boundaries
  • Separating groups of parts
  • Reducing total cutting time

Don't use shrink wrap for:

  • Single objects (use Contour instead)
  • Parts that need individual boundaries
  • Precise rectangular cuts

How Shrink Wrap Works​

Shrink wrap creates a boundary using a computational geometry algorithm:

  1. Start with a convex hull around all objects
  2. Shrink the boundary inward toward the objects
  3. Wrap tightly around the object group
  4. Offset outward by the specified distance

The result is an efficient cutting path that follows the overall shape of your parts while maintaining clearance.

Creating a Shrink Wrap Operation​

Step 1: Arrange Objects​

  1. Place all parts you want to wrap on the canvas
  2. Position them with desired spacing
  3. Multiple separate groups can be shrink-wrapped together

Step 2: Select Objects​

  1. Select all objects to include in the shrink wrap
  2. Can be different shapes, sizes, and types
  3. All selected objects will be wrapped together

Step 3: Add Shrink Wrap Operation​

  • Menu: Operations Add Shrink Wrap
  • Right-click: Context menu Add Operation Shrink Wrap

Step 4: Configure Settings​

Key Settings​

The step settings dialog has three tabs: Step Settings, Laser, and Post Processing. Settings are described in tab order below.

Shrink Wrap​

Shrink Wrap step settings

The Shrink Wrap group on the Step Settings tab controls how the hull fits around the content.

Smoothness​

Controls how closely the boundary follows object shapes:

High smoothness:

  • Follows objects more closely
  • More complex path
  • Longer cutting time
  • Less material waste

Low smoothness:

  • Simpler, more rounded path
  • Shorter cutting time
  • Slightly more material waste

Recommended: Medium smoothness for most cases

Cut Side​

Controls where the laser cuts relative to the shrink-wrap path:

Cut SideDescriptionUse For
CenterlineCuts directly on the pathStandard cutting
OutsideCuts outside the boundaryMaking the cut slightly larger
InsideCuts inside the boundaryMaking the cut slightly smaller

Offset Distance​

Offset (mm):

  • How much clearance around the parts
  • Distance from objects to the shrink-wrap boundary
  • Larger offset = more material left around parts

Typical values:

  • 2-3mm: Tight wrap, minimal waste
  • 5mm: Comfortable clearance
  • 10mm+: Extra material for handling

Why offset matters:

  • Too small: Risk cutting into parts
  • Too large: Wastes material
  • Consider: Kerf width, cutting accuracy

Laser settings​

Laser settings

Power, speed, and laser head selection live on the Laser page of the step settings dialog.

Like other cutting operations:

Power (%):

  • Laser intensity for cutting
  • Same as you'd use for Contour cutting

Speed (mm/min):

  • How fast the laser moves
  • Match your material's cutting speed

To cut the boundary more than once, add a Multi-Pass post-processor.

Use Cases​

Batch Part Production​

Scenario: Cutting 20 small parts from a large sheet

Without shrink wrap:

  • Cut full sheet boundary
  • Waste all material around parts
  • Long cutting time

With shrink wrap:

  • Cut tight boundary around part group
  • Save material for other projects
  • Faster cutting (shorter perimeter)

Nesting Optimization​

Workflow:

  1. Nest parts efficiently on sheet
  2. Group parts into sections
  3. Shrink wrap each section
  4. Cut sections separately

Benefits:

  • Can remove finished sections while continuing
  • Easier handling of cut parts
  • Reduced risk of part movement

Material Conservation​

Example: Small parts on expensive material

Process:

  1. Arrange parts tightly
  2. Shrink wrap with 3mm offset
  3. Cut free from sheet
  4. Save remaining material

Result: Maximum material efficiency

Combining with Other Operations​

Shrink Wrap + Contour​

Common workflow:

  1. Contour operations on individual parts (cut details)
  2. Shrink wrap around the group (cut free from sheet)

Execution order:

  • First: Cut details in parts (while secured)
  • Last: Shrink wrap cuts group free

See Multi-Layer Workflow for details.

Shrink Wrap + Raster​

Example: Engraved and cut parts

  1. Raster engrave logos on parts
  2. Contour cut part outlines
  3. Shrink wrap around entire group

Benefits:

  • All engraving happens while material is secured
  • Final shrink wrap cuts entire batch free

Post-Processing​

Shrink Wrap post-processing settings

Shrink Wrap operations support several post-processing options:

Part Spacing​

Optimal spacing:

  • 5-10mm between parts
  • Enough for shrink wrap to distinguish separate objects
  • Not so much that you waste material

Too close:

  • Parts may be wrapped together
  • Shrink wrap may bridge gaps
  • Difficult to separate after cutting

Too far:

  • Wastes material
  • Longer cutting time
  • Inefficient use of sheet

Material Considerations​

Best for:

  • Production runs (many identical parts)
  • Small parts from large sheets
  • Expensive materials (minimize waste)
  • Batch cutting jobs

Not ideal for:

  • Single large parts
  • Parts filling entire sheet
  • When you need full sheet cut

Safety​

Always:

  • Check that boundary doesn't overlap parts
  • Verify offset is sufficient
  • Preview in 3D Preview
  • Test on scrap first

Watch for:

  • Shrink wrap cutting into parts (increase offset)
  • Parts moving before shrink wrap completes
  • Material warping pulling parts out of position

Advanced Techniques​

Multiple Shrink Wraps​

Create separate boundaries for different groups:

Process:

  1. Arrange parts into logical groups
  2. Shrink wrap Group 1 (top parts)
  3. Shrink wrap Group 2 (bottom parts)
  4. Cut groups separately

Benefits:

  • Remove finished groups during job
  • Better organization
  • Easier part retrieval

Nested Shrink Wraps​

Shrink wrap within a larger boundary:

Example:

  1. Inner shrink wrap: Small detailed parts
  2. Outer shrink wrap: Includes larger parts
  3. Contour: Full sheet boundary

Use for: Complex multi-part layouts

Clearance Testing​

Before production run:

  1. Create shrink wrap
  2. Preview with 3D Preview
  3. Verify clearance is adequate
  4. Check no parts are intersected
  5. Run test on scrap material

Troubleshooting​

Shrink wrap cuts into parts​

  • Increase: Offset distance
  • Check: Parts aren't too close together
  • Verify: Shrink wrap path in preview
  • Account for: Kerf width (laser beam width)

Boundary doesn't follow shapes​

  • Increase: Smoothness setting
  • Check: Parts are properly selected
  • Try: Smaller offset (might be wrapping too far out)

Parts are wrapped together​

  • Increase: Spacing between parts
  • Add: Manual contours around individual parts
  • Split: Into multiple shrink wrap operations

Cutting takes too long​

  • Decrease: Smoothness (simpler path)
  • Increase: Offset (straighter boundaries)
  • Consider: Multiple smaller shrink wraps

Parts move during cutting​

  • Add: Small tabs to hold parts (see Holding Tabs)
  • Use: Cutting order: inside to outside
  • Ensure: Material is flat and secured
  • Check: Sheet isn't warped

Technical Details​

Algorithm​

Shrink wrap uses computational geometry:

  1. Convex hull - Find outer boundary
  2. Alpha shape - Shrink toward objects
  3. Offset - Expand by offset distance
  4. Simplify - Based on smoothness setting

Path Optimization​

The boundary path is optimized for:

  • Minimum total length
  • Smooth curves (based on smoothness)
  • Efficient start/end points

Coordinate System​

  • Units: Millimeters (mm)
  • Precision: 0.01mm typical
  • Coordinates: Same as workspace