Cura is a free and beginner-friendly slicing software that converts 3D models into G-code, a language the 3D printer can understand. The internal structure of a 3D-printed object is known as the infill pattern. Cura’s latest version (5.3) includes 14 types of infill patterns that vary in terms of strength, flexibility, and final surface smoothness of the printed object.
Whether you are a beginner or an expert in 3D printing, the knowledge of infill patterns is crucial to ensure the desired outcomes.
Infill patterns are not visible externally, but they hold a huge significance when it comes to giving strength and flexibility to the printed object.
In this article, we’ll discuss various Cura infill patterns and know how to choose one of them. It is a complete guide that explains the infill patterns according to their applications, so make sure to read till the end.
The Role of Infill Density and Infill Patterns Explained
3D printing is the process of creating three-dimensional objects by adding materials in layers.
You might be surprised to know that the inside of any 3D-printed object is made up of actual materials and hollow space.
The biggest advantage of 3D printing technology is that it allows users to adjust the internal hollowness to reduce manufacturing time, cost, material usage, and more.
When it comes to the strength and weight of the printed object, the amount of plastic used plays a crucial role and is known as infill density. Objects that are printed for decoration and entertainment purposes have an infill density as low as 20%.
So, what are infill patterns, and why are they important?
You can use infill patterns to adjust the infill density from 0% to 100% (solid).
Simply, it represents how you add layers while printing to obtain the desired infill density and strength.
It is obvious that higher infill densities will increase the solidity of the printed object.
Most experts generally rely on infill densities between 20% to 50% to achieve desired print quality and reduce the cost of raw materials such as 3D printing filaments.
So, while 3D printing, it all starts with choosing the right infill density for your product and then choosing the best infill pattern from the following list.
But before we start discussing 14 different infill patterns by Cura, let us understand the use cases of infill patterns,
Types of Infill Patterns and Applications
You have the option to choose from various 2D and 3D infill patterns such as lines, zig-zag, octet, and gyroid. It all affects the void space inside the printed object and helps you determine its strength.
Note that not all types of geometries are quick and cost-effective; it all boils down to your specific application and use case.
Let us categories infill patterns in four different categories:
Quick 2D infills – Figurines
Objects that are printed for visual and decoration purposes don’t need to be strong.
In that case, you can keep the infill density to as low as 10%. Here the strength is not the primary concern, but you should focus on the surface smoothness of the final product.
Infill patterns such as lightning, lines, and zig-zag are best fit to print those objects quickly and efficiently.
Strong 2D infills – Standard Prints
Everyday objects that may be subjected to moderate handling or put under stress need to be printed with added strength.
In general, you need to consider the infill density between 10% to 30%.
Medium-strength infill patterns such as grid, triangles, and tri-hexagon should be used in such cases.
3D infills – Functional 3D Prints
Day-to-day 3D printed objects or functional 3D prints subjected to heavy loads must have high strength and weight.
As a general rule, you must ensure that such functional prints will be equally strong in all directions. Choose from infill patterns such as cubic, cubic subdivision, quarter cubic, octet, and gyroid for such products.
Additionally, make sure to keep the infill density between 30% to 50% to have the desired strength.
3D concentric infills – Flexible 3D Prints
People planning to print flexible objects should choose infill patterns such as cross, concentric, and 3D infill patterns.
There is a range of flexible filaments available for printing such objects.
The right selection of infill patterns and filaments is the key to success here.
List of 14 Best Cura Infill Patterns
Here is a list of Cura Infill Patterns as per the latest version, Cura 5.3.
- Grid
- Lines
- Triangles
- Tri-hexagon
- Cubic
- Cubic (Subdivision)
- Octet
- Quarter Cubic
- Concentric
- Zig-zag
- Cross
- Cross 3D
- Gyroid
- Lightning
Now without any further ado, let us discuss each in detail.
#1 – Grid
This infill pattern creates a square shape by forming two perpendicular lines.
Grid is a 2D infill pattern most useful in quickly printing objects.
This cross-over pattern is one of Cura’s most used and simplest infill patterns.
Prints that require moderate amounts of strength use Grid infill patterns. It offers strength, speed, and simplicity in multiple directions. Grid is well-known as one of the strongest infill patterns in Cura for the loads along the XY-axis.
It is very similar to the lines (an infill pattern discussed below), but how the lines are positioned differs. It is mainly because the lines travel in two directions.
Pros
- Simple internal structure
- Maximum strength in the vertical direction
- Smooth surface finish
- Support for the top surface
- Excellent strength in the direction of the formed lines
Cons
- Weak in the horizontal direction
- Not enough strength in the diagonal direction
#2 – Lines
Every line runs parallel to each other, as shown in the above image in the Lines infill pattern. The printer deposits filaments in unidirectional lines for each layer and changes direction by 90 degrees for subsequent layers.
It is also known as the rectilinear infill pattern.
Such infill patterns are suitable for printing models and figurines. It uses less material compared to most of the infill patterns. Overall, Lines infill pattern is simple, fast, and cost-effective.
But one thing to note is that the Lines pattern lacks strength in vertical and horizontal directions. In other words, it is useful for objects that are printed for visual or decoration purposes.
Like Grid, it is a simple infill pattern that quickly creates objects with faster print speeds.
Pros
- Best for printing figurines
- Simple internal structure
- Faster print speeds
- Smooth surface finish
Cons
- Weak in both vertical and horizontal direction
- Not suitable for objects that are subjected to heavy loads
#3 – Triangles
The Triangles infill pattern includes interconnected triangles in a 2D mesh.
This infill pattern is formed by three different lines intersecting at equilateral angles of 60 degrees.
It is popular for offering strength when the loads are applied perpendicular to the object’s face. This infill pattern with interconnected triangles is particularly strong in every horizontal direction.
Triangles infill pattern is used for everyday and standard prints. In contrast to the Grid, it makes triangles that give extra strength to printed objects.
One of the main drawbacks of this infill pattern is that the print flow is interrupted at the point of intersection.
Pros
- Best for standard prints
- Uniform strength in each horizontal direction
- Excellent shear-resistance
Cons
- Weak strength at high infill densities
- Flow interruptions
#4 – Tri-hexagon
It is one of the strongest infill patterns by Cura that combines hexagons and triangles for the efficient use of raw materials.
The Tri-hexagon infill pattern includes small triangles and large hexagons, as shown in the above image.
It creates three separate lines in three different directions and ensures that none intersect in the same position.
The arrangement of hexagons and triangles allows excellent resistance to shear forces. Additionally, it minimizes bowing issues caused by poor print cooling.
So, the Tri-hexagon can be used for standard and visual prints that require additional strength.
Pros
- Uniform strength in each direction
- High strength in the horizontal direction
- Excellent shear-resistance
Cons
- The top smooth surface is achieved by layering multiple layers
#5 – Cubic
Cubic is one of the most commonly used Cura infill patterns. It is the first 3D infill pattern on this list.
It prevents pillowing on the printed surface by avoiding long pockets of hot air.
In this infill pattern, cubes are titled and stacked to create a 3D dimensional pattern.
The Cubic infill pattern provides strength in both vertical and horizontal directions. It has a unique orientation to prevent overhangs and extrusions without support.
This infill pattern suits functional prints requiring high strength along all axes.
Pros
- Excellent strength in all directions
- Suitable for functional prints
- Reduced pillowing effect
Cons
- None
#6 – Cubic (Subdivision)
It is an upgraded version of the Cubic infill pattern and offers benefits such as reduced material usage and improved printing speed.
It creates cubes of different sizes, including larger ones in the center and smaller cubes in the outer areas. You will also notice that the large cubes are subdivided into eight small cubes.
Cubic Subdivision is the best choice for quickly printing functional parts with higher infill densities. Note that the reduced material usage and improved printing time are subjected to the complex pattern it creates.
Moreover, when it comes to slicing, it takes comparatively longer time than other infill patterns by Cura.
Pros
- Excellent strength in all directions
- Filament usage is low
- Improved surface smoothness compared to Cubic infill pattern
- Suitable for higher infill densities
- Reduced pillowing effect
Cons
- Slicing is a bit slower compared to other infill patterns
- Low strength in the middle of the final product
#7 – Octet
Octet infill pattern creates pyramid shapes and stacks them one above another to give ultimate strength to the printed object.
It is also known as the Tetrahedral infill pattern by Cura. It is a 3D infill pattern.
The above image shows that the pattern consists of tetrahedrons and cubes. Multiple infill lines are created to achieve the desired internal structure.
It also helps you reduce the pillowing effect. Octet is the best fit for objects requiring robust internal strength to handle heavy loads.
The major drawback of the Octet infill pattern is the poor surface finish due to the long bridging distance.
You can use this infill pattern to create high-strength functional parts such as thin mechanical parts.
Pros
- Robust internal structure
- Excellent strength in all directions
- Reduced pillowing effect
Cons
- Poor top surface smoothness
#8 – Quarter Cubic
The Quarter Cubic 3D infill pattern is very similar to the Octet, except that half of each pyramid is shifted with respect to the other half.
In simple words, you will notice the combination of tetrahedrons and truncated tetrahedrons inside the printed object, as shown in the above image.
The Quarter Cubic infill pattern is particularly useful for printing thin functional parts that demand high internal strength and are subjected to high loads.
Similar to the Octet, the smoothness of the top surface is poor due to the longer bridging distance.
Pros
- Suitable for thin functional parts with high strength
- Robust internal structure
- The pillowing effect is reduced
- Excellent strength in all directions
Cons
- Poor top surface smoothness
#9 – Concentric
A concentric infill pattern creates water wave-like structures inside the 3D-printed object. It resembles concentric ripples in the water.
It is a 2D infill pattern suitable for printing flexible objects using flexible filaments.
The creation of parallel rings is responsible for the flexibility of the object. You also need to make sure to keep the infill density low.
On the other hand, if you increase the infill density, the object will become more rigid, and the load distribution will be uniform.
It is the strongest infill pattern when it comes to infill density of 100%, as the lines don’t intersect.
Pros
- Suitable for flexible prints
- Even load distribution in all directions
- More strength in the vertical direction
Cons
- Circular shapes are not the best fit for 100% infill density
#10 – Zig-zag
It is another commonly used infill pattern by Cura that resembles Lines. It creates a 2D grid where only one axis is printed per layer.
The nozzle creates a new line whenever it reaches the outer wall in the Lines infill pattern. However, in the case of Zig-zag, the nozzle goes back on itself when it reaches the outer wall to create one long line and reduce the flow interruptions.
In contrast to Concentric, the Zig-zag pattern works best at 100% infill density when it comes to circular shapes.
One of the main benefits of choosing Zig-zag is that the nozzle doesn’t have to retract, so you don’t have to face oozing associated with low-viscosity filaments like PRTG.
It is also known as one of the best infill patterns by Cura for a smooth top surface.
Pros
- Smooth surface finish
- Suitable for circular shapes at 100% infill density
- Prevents oozing effect
Cons
- Low strength in both vertical and horizontal direction
- Bad shear resistance
#11 – Cross
The Cross infill pattern is used for printing flexible objects. It creates grids of fancy crosses.
Additionally, it doesn’t create any long straight horizontal lines.
It is a 2D infill pattern.
The space between crosses is responsible for the bending and twisting of the object. It also avoids oozing, similar to the Zig-zag infill pattern, by preventing nozzle retraction.
You will notice high flexibility in the horizontal direction with this infill pattern. When it comes to strength, you will notice that the strength is high in the vertical direction compared to the horizontal direction.
The printed object will be soft and flexible. However, you must note that the lack of straight lines implies weaker internal strength.
Pros
- Suitable for flexible prints
- No print restrictions
- High strength in vertical directions than in the horizontal direction
Cons
- Weak in all directions
#12 – Cross 3D
The Cross 3D infill pattern is similar to the Cross but creates inclined lines as it grows. Additionally, it creates slightly rigid objects compared to the Cross infill pattern.
This upgraded version of Cross creates curves with spaces inside the print for flexibility and softness. Additionally, it eliminates the undesirable vertical strength of the Cross pattern.
The overall strength in all directions is relatively weak, which makes it the right choice for flexible printing.
In contrast to the Concentric and Cross patterns, the Cross 3D infill pattern provides better flexibility while eliminating the need for nozzle retraction and preventing oozing.
Pros
- Suitable for flexible prints
- Prevents oozing
- Avoids nozzle retraction
- Creates soft prints
Cons
- Weak in all directions
- Slicing is a bit slower compared to other infill patterns
#13 – Gyroid
Gyroid is a unique 3D printing infill pattern by Cura that resembles the wave-like inner structure of Concentric. It is a high-strength infill pattern that can be used for flexible 3D printing.
But note that this infill pattern offers lower flexibility and softness than the dedicated, flexible infill patterns.
It creates strong final prints with uniform strength in multiple directions. You can print objects for heavy applications subjected to various stress types.
Gyroid creates permeable 3D prints. So, if you need an object requiring fluid passage, this infill pattern is the right choice.
This pattern creates interesting prints and is popular for visually appealing 3D objects using transparent filaments.
The patterns created by Gyroid are complex, so slicing software like Cura takes longer than usual to slice the model.
Pros
- High-strength infill pattern
- Uniform strength in all directions
- Suitable for flexible 3D prints
- Good shear resistance
Cons
- Slicing is a bit slower compared to other infill patterns
- Creates huge G-code files
#14 – Lightning
The lightning infill pattern is similar to lightning bolts, as shown in the above image. It was recently introduced in December 2021 during the launch of the Cura version 4.12.
The basic concept here is to support the internal structure and strengthen the outer walls. If you look at the image carefully, you will notice that the infill density becomes denser towards the outer walls of the printed object.
It is useful in areas where creating infill is challenging. Lightning infill also reduces the amount of infill, saving materials and production costs.
Another main benefit of using Lightning infill is fast printing speed.
Lightning infill may sound interesting, but it requires experience and knowledge.
Pros
- Suitable for prints that require low strength
- Minimal material usage
- Faster print speed
- Lightweight prints
Cons
- Not the best fit for complex prints that are subjected to various types of strength
Things to consider while choosing the infill patterns
1. Gradient and Gradual Infill
When it comes to 3D-printed objects and internal structures, people consider the inside of the object to be uniform.
However, that is not the case.
It can be higher or lower along any axes, including the X, Y, and Z-axis.
It all boils down to the desired strength and stiffness of the final product.
You can use the Gradient infill pattern to have more strength towards the object’s perimeter. It acts in X and Y axes while printing. It is not a native feature in Cura, but you can use a Python script to achieve this. It uses less material and, at the same time, gives extra strength to printed objects.
On the other hand, Gradual infill works in the Z-axes. It simply means you will have higher infill density near the top of the print. It saves time and material.
Gradual infill is useful in the case of printing objects where we need extra strength at the end.
2. Skin
The top and bottom layers of the printed object are known as the skin. It impacts the object’s print speed, material usage, weight, and final strength.
You can control the overlap between the outer walls and the inside of the print using a setting called “Skin Overlap Percentage.” Here the higher overlap percentage represents improved attachment of infill.
3. Filament Type
There are a range of 3D printing filaments available in the market. The most popular ones include ABS, PETG, nylon, and PLA+.
Infill densities decide the amount of filaments needed to be used. Additionally, you can adjust the thickness of the infill line (material layer) to improve print speed and time.
So you must be careful when choosing the desired infill density and pattern for your final print.
In other words, infill density and pattern affect the material usage, and so does the cost of production.
You can choose the infill density between 0% to 100%, but it solely depends upon the model’s purpose.
4. Direction of Force and Infill Line Orientation
The complete knowledge of applied force helps you determine the orientation of the infill pattern to maximize internal strength.
Note that the final strength of the infill patterns depends upon the direction. You should always try to orient the layers parallel to the direction of the force.
If the walls are diagonally aligned, you need to adjust the direction of the lines to ensure maximum strength and flexibility.
By default, the infill line orientation is set at 45 degrees to maximize strength and printing speed. It is possible to change the direction of infill lines using available settings.
5. Print Speed
As discussed previously, you can adjust the angle of the infill lines and the thickness of the infill layer to enhance the printing speed and time.
Users are free to adjust the width and flow rate during the printing process.
Print speed is mainly affected by the infill patterns.
So, make sure to play around with the different infill patterns discussed above to get the maximum print speed for your model and its particular needs.
Lightning is known for the fastest print times from all infill patterns discussed above. You can also choose concentric, grid, and triangle infill patterns for quickly printing 3D objects.
Conclusion
Choosing the right infill pattern from the 14 options available by Cura is challenging.
By reading this comprehensive guide, I hope you have gained enough knowledge to choose the one that best fits your application.
Finally, note that no single infill pattern can withstand the needs of your 3D-printed objects in the long run. They need to be explored and carefully picked up to ensure the desired strength.
Here are the major things that need to be considered,
- Strength
- Visual Appearance
- Production cost
- Flexibility
- Surface smoothness
No single infill pattern ticks all of the above boxes, but if you are just starting out, choose a tri-hexagonal that offers the best combination of strength, material usage, and print speed.
Finally, in case you have any doubts about Cura infill patterns, then comment below.
