When you 3D print a part, it is rarely 100% solid plastic. Printing solid parts takes days and wastes expensive filament. Instead, slicers use an internal honeycomb structure called Infill.
What is Infill Density?
Density is measured in percentages (0% to 100%).
- 0% (Vase Mode/Hollow): Fast, but extremely fragile.
- 10% - 15%: Standard for decorative items, figures, and prototypes.
- 20% - 30%: The sweet spot for mechanical automotive parts.
- 50%+: Yields diminishing returns. If you need a stronger part, add more outer walls (perimeters) rather than increasing infill above 50%.
The Best Infill Patterns
1. Grid / Rectilinear
- The default in most slicers. Fast and simple. However, the nozzle crosses over its own paths, which can cause grinding noises on high-speed printers.
2. Gyroid
- The Modern Standard. Gyroid prints a 3D wave pattern that is equally strong in all directions (X, Y, and Z). It prints relatively fast, doesn't cross its own paths, and is highly recommended for mechanical car brackets.
3. Cubic
- Creates 3D cubes inside the model. Excellent strength-to-weight ratio for bulky structural parts.
4. Lightning
- A new feature in Cura and PrusaSlicer. It only generates infill where it is absolutely needed to support the top layers. It is incredibly fast and saves huge amounts of filament, but provides almost zero mechanical strength.
DesignMak Pro-Tip: For all our automotive clips and brackets, we recommend 3 to 4 outer walls (perimeters) and 25% Gyroid infill. This guarantees the part won't snap under automotive stress.