Infill Patterns and Density Guide for 3D Printing
Infill is the internal structure inside a 3D printed part. It affects strength, weight, material usage, print time, and cost.
1. Infill Density
0–10% — Very light, fragile. Only for display models not handled.
15–25% — Light, moderate strength. Good default for prototypes.
30–50% — Strong. Good for functional parts under moderate load.
50–75% — Very strong. Structural parts, jigs, fixtures.
100% — Solid. Maximum strength and weight. Required for watertight parts.
2. Common Infill Patterns
Grid — Simple crosshatch. Balanced strength in X and Y. Fast to print. Good default.
Gyroid — Organic, curved structure. Equal strength in all directions. Best for parts loaded from multiple angles. Slightly slower to print.
Triangular — Strong in compression. Good for parts bearing vertical loads.
Honeycomb — High strength-to-weight ratio. Popular for aerospace and drone parts.
Lightning — Minimal material, supports only the top surface. Fastest and cheapest. Only for visual models.
3. When Infill Matters
Infill primarily applies to FDM printing. Other technologies handle it differently:
SLA: Parts are typically printed solid or hollow with drain holes. No traditional infill.
Industrial SLA — Same as SLA but for large-format parts up to 1000 x 1000 x 600mm
MJF: Parts are solid by default. Can be hollowed with escape holes to reduce cost.
FGF — Very large parts up to 1800 x 1200 x 1100mm, 3mm min wall thickness
4. Cost Impact
Higher infill = more material + longer print time = higher cost. For FDM parts:
Going from 20% to 100% infill roughly doubles the cost and print time
Going from 20% to 50% adds about 30–40% to cost
5. Hollow Parts & Ribbing
For MJF and SLA parts that are hollowed to reduce cost, internal ribbing may be recommended to maintain structural integrity. Ribs add strength without significant material use, and our team may suggest them during file review if your part geometry would benefit. If you are hollowing a part yourself, consider adding internal ribs at stress points and along large flat surfaces to prevent warping or collapse.
6. How to Specify
Include your infill preference in your order notes. If you’re not sure, our default settings balance strength and cost. For structural applications, tell us how the part will be loaded and we’ll optimize accordingly.