Start with the part’s roof, walls and job. A wide nameplate needs support under its flat top. A narrow clip may consist almost entirely of perimeters. Giving both parts the same “strongest infill” can spend filament in a region that barely exists.
What changes between the three patterns
| Pattern in PrusaSlicer | What you can see in layer preview | A reason to choose it |
|---|---|---|
| Rectilinear | Parallel lines on one layer, turned on the next | A broad roof needs evenly distributed support with a simple toolpath. |
| Grid | Both line directions cross on the same layer | A regular lattice is useful, and the nozzle can traverse the crossings cleanly. |
| Gyroid | Curved paths change through the height without same-layer crossings | The part has a substantial core and you want support in several directions without grid intersections. |
Prusa documents material buildup at grid crossings and the difference in top-layer support between grid and rectilinear. Its infill guide treats density and pattern as separate choices. Pattern properties describe the interior geometry. They do not establish the load capacity of a particular printed part. Prusa infill patterns · Prusa infill settings
A preview comparison you can repeat
Use a model with both a flat top and a narrow tab. Slice three copies with the same orientation, filament, density, perimeter count, top layers and layer height. Change only the pattern. At the layer immediately below the first solid top, inspect the distance the top strands must span. Now move the slider to the tab. If its cross-section shows only perimeter paths, none of the three infills changes the material inside that tab.
Write down the slicer’s estimated time and filament for each copy. Equal density settings need not give identical estimates on a finite shape. For a display piece, choose the least costly option whose preview supports the roof. If the tab must resist repeated bending, make a separate comparison that changes the wall design or perimeter count. Prusa’s layer and perimeter guide explains why walls matter to part strength. Layers and perimeters
For a wide box lid, that process may favor rectilinear even if gyroid worked well in a thick handle. For a thin-walled tray, it may show that changing infill does almost nothing. To convert the slicer’s material estimates into job costs, use the filament and energy calculator .