3D Printing Infill. Ultimate Guide for Choosing Infill Percentage.

by Mike Brooks | Last Updated: October 27, 2021

3D printing objects have two distinct zones. They consist of the outer shell that users refer to as the wall and infill or the inner parts.

3D Printing Infill

Also, correctly manufactured, the two values determine the mechanical properties of a 3D model, such as resistance, the finish outlook, time, and print cost.

The 3D printing enthusiasts may easily influence the outcome of the shell but will struggle to control the object infill.


However, the Cura 3D enables you to choose the structure, shape, and percentage of the material inside the 3D object.

A slicer program contains programs with instructions set when designers translate the 3D models into G-Code instructions. The parameters fall under the infill density or the infill pattern.

If you manage to determine the correct balance between the infill density and infill pattern, you get a 3D printed part with the proper strength, structure, weight, and buoyancy.

The article provides adequate information to help you understand and handle your printer infill settings and find the best infill patterns.

What Is Infill 3D Printing?

The infill refers to the plastic materials deposited internally in a 3D printed model. Also, it relates to the internal structure of a 3D-printed part. As such, it remains invisible once the material printing process ends.

What Is the Importance of Infill 3D Printing?

The 3D printing infill plays several critical roles and functions towards a practical 3D printing process. The list below provides the importance of 3D printing infill from the highest to the lowest in utility.

How Many Infills Do You Need for 3D Printing?

What Is Infill Density?

3D print infill density refers to the “fullness” or “compactness” of the part. In slicers, infill density remains captured in percentages with 0% referring to a hollow portion; below 50% shows a low infill percentage and over 50% attesting to a higher infill percentage.

Also, a percentage of 100% signifies a substantial 3D print object.

3D print infill significantly impacts the weight of the printed object. Also, while 3D Printing, the printer deposits molten layers that give the print a gradual infill as the infill lines combine top and bottom layers to make an infill overlap, providing the 3D print part with a higher infill density.

In the final analysis, the fuller the interior of a part, the heavier the part. Additionally, density impacts print time and consumption of infill material.

So, thicker layers and infill density combined with elements such as layer height determine overall 3D printed object strength.

Any standard print requires 15-50% infill density. It remains a quantity that guarantees a low print time, conserves material, and provides excellent print strength.

Always take note that the higher the infill density, the lesser the print flexibility.

Recommended 3D Print Infill Settings

What 3D Printing Infill Is the Strongest? [Infill Patterns]

It refers to the inner structural composition of your 3D print. Also, different infill patterns depend on the intended use of a 3D image.

More importantly, infill patterns determine the 3D object strength, weight, flexibility, and printing time. Notably, the market enjoys numerous infill lines, from the simple infill line to the most complex infill lines.

Your choice of infill pattern will depend on the 3D print strength you desire. For instance, line infills are not as stable as cubic patterns.

1. Low Strenght

a) Line Infills Pattern

3D printer draws parallel lines in only a single direction per layer. Also, in the next layer, the printer rotates the lines by 90 degrees. This pattern remains suitable for decorative and standard models that don’t need a high level of object stability.


b) Zigzag Pattern

It’s pretty similar to the line pattern. Also, the printers print lines in one zigzag motion. The flow remains less interrupted, offering a smooth printing experience.

Zigzag patterns provide prints that may not be stable, making them more suitable for use in support structures.


2. Medium Strenght Patterns

a) Grid Pattern

Quite similar to the lines pattern. Additionally, it boasts of two-dimensional lines per layer instead of one. It’s a quality that increases print strength but accounts for the use of more filaments.

It enjoys average to short time printing speed, as its internal structure remains a straightforward one.


b) Triangular Patterns

The triangular infill remains anchored on a two-dimensional mesh of triangles. Additionally, the triangular pattern remains applicable in day-to-day objects that need maximum resistance in the outer wall. Moreover, achieving high resistance and ultimate strength on the exterior walls depends on aligning the lines at an infill angle of 45 degrees.


c) Tri-Hexagonal Pattern

This pattern produces a unique mixture of triangles and hexagons when used. Additionally, it makes accurate shapes and strong patterns with a low material consumption rate.

Its short lines make the connection to all sides easy. Also, it gives you fewer challenges when you try to bend your 3D print.


3. The High Strength Patterns

a) The Cubic Pattern

It consists of 45 degrees tilted and stacked cubes. Notably, the tilting of the cubes presents a triangular and horizontal appearance on the plane.

More importantly, the cubic pattern is strong in all directions. Unfortunately, the pattern consumes more time and filament materials than other patterns.


b) The Cubic Sub-division Pattern

This pattern remains tailor-made to respond to the high material consumption of the regular cubic pattern. The designers made the cubes bigger at the center of the object so that any time cubes hit the shell of the things, and they divided themselves into smaller cubes.

As a result, the outer areas remain more complicated than the central areas. Thus, you will need less plastic for the inner parts.


Does Infill Increase Strength?

Yes, infill filament increases the strength of the 3D printed parts depending on the percentage of filament density used to manufacture it.

As a 3D printing hobbyist, the percentage of filament density you need to use will solely depend on the 3D object you intend to print.

For example, for a prototype where form remains essential, you can use lower infill density that will allow you to save cost and time.

While if you 3D print a model meant for loading, you will need to use a higher infill percentage to achieve a higher print strength.

Suppose you print a 3D object with a 30% filament density percentage and print another 3D model using a 10% filament density percentage. In that case, it means the first object will remain three times stronger than the second print.

Which Infill Pattern Is Fastest?

If you seek the best infill pattern for speed, you need to look for a few infill parameters. Notably, infills based on straight lines, less material used, and the slightest movement provide the fastest speed available to 3D print.

Therefore, the lines pattern or the rectilinear pattern remains the best infill pattern for speed in 3D printing. Furthermore, patterns with a tendency for most directional changes take longer to print than the line patterns.

The best strength-to-weight ratio also guarantees faster printing in 3D technology.

Cura Infill Patterns Explained

Cura Application Software

Cura refers to an application software used by 3D printers. Notably, David Brahm founded the software, and he later joined Ultimaker, a 3D printer manufacturing company, as an employee to help maintain the software.

Cura works by slicing the user’s model file into layers. Thus, it generates printer-specific G-codes that help the printer manufacture the physical 3D object.

Simply put, Cura works by converting data of your 3D object to a language that your printer can understand.

Cura and the Infill

Cura provides you with so many benefits as it allows you to customize your 3D printer differently. Additionally, Cura helps you enjoy numerous infill patterns to choose your infill preference.

Also, it serves as an excellent tool for giving your print the requisite strength and minimizes the 3D print weight, saving on the plastic filament.


The article provides information on the 3D print infill, the infill patterns retain different features, and all serve other purposes in the 3D printing industry.

The 3D infill density determines the final strength of the printed object. Also, it influences the quantity of the plastic filament that you need to use, the printing time, and the cost.

More importantly, the 3D infill technology enables the use and application in different industries or personally by 3D hobbyists.

Michael Brooks is the founder of M3DZone.com. He sees a very bright future for 3D printing that's why his mission is to try and make this easy for everyone. Discover your hidden talent and creativity. You can follow here: Facebook, Twitter & Pinterest.