Wood Grain/Swirl Pattern

Wood Grain/Swirl Pattern on Part Surface

A wood grain or swirl-like pattern may appear on printed models. This is expected behavior and not a print quality defect. This is a sign of a highly calibrated printer.

The severity of the pattern can vary depending on:

• Model orientation
• Geometry (curved vs. flat surfaces)
• Print settings and finishing

Note the following:

• The pattern might resemble machining marks, but it is a normal output of the technology.
• Hardware replacements, software reinstallation, or calibration adjustments do not eliminate pixelation-related patterns.
  
  

  Figure 1: Top view —Left : Pattern; Right: Close-up
   

  Figure 2: Side view —Left : Pattern; Right: Close-up
   

  Figure 3: Side view —Left : Pattern; Right: Close-up
   

Possible Causes and Solutions

Inherent Pixelization in 3D Printing

On all 3D printing systems, this visual wood grain or swirl pattern texture is caused by a phenomenon known as pixelization.

• This effect is inherent to layer formation (how material is deposited during printing).
• It can be visible on model side surfaces.
• It can be visible on matte and glossy surfaces and can be observed before and after cleaning.

This pattern does not indicate a system malfunction, calibration issue, or incorrect settings.

Figure 4: Side view with wood grain pattern

Figure 5: Wood grain appearance on glossy surface

Solution: If the visual impact is a concern, try any of these suggested options:

• Rotate the model around the Z-axis during job preparation.
• Change the model orientation so the pattern appears on a less visible surface. This does not eliminate the pattern; it only relocates it to another surface.
• In J7 series printers only, there is an option (Enable Grid Shift) to enable a grid shift in Preferences > PolyJet > Enable Legacy Slicer settings. This applies jitter (additional layer shifts) to blur the pattern.

Figure 6: Enable Grid Shift for reducing wood grain effect (GrabCAD Print)

Figure 7: Left: Pattern not visible; Right: Pattern visible
 

Figure 8: Left: Wood grain visible; Right: After enabling grid shift
 

Preventive Measures:

• Plan model orientation in advance to minimize pattern visibility on critical surfaces.
• Position aesthetic or functional surfaces away from dominant pattern directions.
• Set expectations with stakeholders or customers regarding this inherent appearance.