3D Printing Infill: Patterns, Percentages, and When to Use Each
Infill determines the internal structure of your print. It affects strength, weight, material use, and print time. Here is how to choose the right infill for every application.
What Is Infill?
From the outside, most 3D prints look completely solid. Inside, most of them are not. Infill is the internal structure the printer builds inside a solid-looking model: a repeating geometric pattern that provides structural support without printing entirely solid material.
The infill percentage controls how dense that internal structure is. 0% infill means completely hollow. 100% infill means completely solid. Everything in between is a lattice of varying density.
For most hobbyist prints, the right infill percentage falls between 10% and 25%. Going higher adds print time and material cost without proportional strength gains in most applications. Going to 100% is only necessary for small detail pieces where the size of the model means the time difference is minimal.
Infill Percentage Guide
10-15% — Light
Standard for display pieces, decorative objects, and large prints where internal strength is not critical. Saves significant material and time. The deck box body at 10-15% infill feels solid and handles cards well.
20-25% — Moderate
Good balance for general-purpose prints. Suitable for parts that will be handled regularly. The Lollipop Chainsaw chain links at 25% infill are flexible and durable enough for convention handling.
40-60% — High
For structural parts, hinges, and anything subject to repeated stress. The extra material meaningfully improves impact resistance and rigidity. Significant increase in print time and material use.
100% — Solid
Every OreKo logo cap and mana chip calls for 100% infill. These are small pieces where the time penalty is 10-15 minutes, and the fully solid structure ensures fine raised details do not flex or chip during handling and assembly.
Infill Patterns
The percentage controls density. The pattern controls the geometry of the internal structure. Most slicers offer a dozen or more patterns. For practical hobbyist printing, these four are the most useful:
Lines — parallel lines in a single or alternating direction. Fast to print. Not the strongest but good for display pieces and detail components. OreKo recommends lines at 100% infill for logo caps because the parallel lines produce the smoothest top surface on the cap artwork.
Grid — perpendicular lines creating a grid pattern. Stronger than lines in both X and Y directions. Good general-purpose pattern for functional parts.
Gyroid — a complex three-dimensional curved pattern. Excellent strength-to-material ratio and equal strength in all directions. Slightly slower to print than grid but the best structural pattern for most mechanical applications.
Honeycomb — hexagonal cells. Efficient use of material, good compression strength, visually interesting if the infill is visible through thin walls. Popular for large structural parts.