What's the Strongest Infill Pattern? Here is What I Think

What is the Most Reliable Infill Pattern?

Infill patterns are commonly used in production to increase the strength or quality of a product. While three cubes may all look similar on the outside, what is inside can be different simply based on the infill pattern used.

Since 3D printing is commonly used to reduce cost and waste, using the right infill pattern can make or break a project, literally. A lower strength infill pattern will do the job for projects that need little support or overall strength. Others may require a more complex pattern. Infill patterns can be broken down into four main categories.

Models and Figures: These are the most straightforward patterns and often consist of a straight-line or a zigzag. While they can be useful, they are among the weakest infill patterns used in production and 3D printing.
Standard: Most commonly used, a standard infill pattern is what is mostly used in many 3D printing production industries. Triangle, grid, and hexagons make for a unique pattern that is simple to execute but also provides decent strength.
Functional: For projects that need serious strength, functional patterns are the most complex and most expensive. These patterns consist of cubic, cubic subdivision, octet, quarter cubic, and gyroid, to name a few.
Flexible: If you are not sure how strong or supportive you need a pattern to be, flexible patterns are probably best for you. They can range anywhere from weak to strong, depending on what you use. Concentric, cross and cross 3D are the most common flexible infill patterns.

Among most 3D printers, they will tell you that the cubic pattern is the strongest infill pattern around. Not only is it supportive, but it has a higher density than most others. While this is the strongest, it does come with a higher production cost, and it takes more time than a line infill pattern would.

Something else to consider is if you actually need the strongest infill pattern for the project you are working on. There are quite a few ways to increase the strength and quality of a model or a project without having to absorb the increased timeline or the higher material and production costs.

Why is Cubic (Honeycomb) the Strongest Infill Pattern?

As you may know, there are quite a few different infill patterns to choose from. With so many patterns out there, what makes cubic the strongest pattern? One of the most significant reasons why people choose this pattern is because of the benefits it provides to a project or model.

Here are the main benefits of a cubic infill pattern:

Provides equal support on all surfaces of the model as opposed to focusing solely on one area.
Most efficient and prints quicker than similar strength infill patterns.

Different Types of Infill Patterns

Although there are only four main categories when it comes to infill patterns, each category can be further broken down into different types of patterns. Considering that some of these infill patterns work best on 2D or 3D objects, it is essential to consider what you are using infill for.

Models and Figurines

The most straightforward category involves models and figurines. Infill patterns are often not needed to have immense strength or a lot of support for their projects. These patterns have a lower density, but they can be produced at a smaller cost and much quicker than most other patterns.

Lines: This infill pattern uses multiple lines to fill in an area. There may be additional layers used to add strength or fill in different portions of a project.

Zigzag: Although this looks similar to a line infill pattern, a zigzag pattern uses one continuous line of filament that can be adjusted based on the shape and size of what you are creating.

Models and figurine infill patterns have their strengths and weaknesses. For example, you are most likely going to spend much less on actual production costs, and you are going to see a short period of time in which it is going to take to produce the pattern.

One way to improve the strength of these patterns is by using multiple layers. Since these are simple designs, you could also increase the filament quality that you are using to maximize strength and support in all areas of your model or project.

Standard Infill Patterns

For projects that need an average amount of strength, standard infill patterns reign supreme. These are more complicated than lines or zigzags but only offer a mediocre amount of support. If you are still working with a 2D image, standard patterns will offer you the ability to provide additional strength without extra bulk or cost.

Grid: A grid essentially consists of two different line patterns intertwined. There will be a line pattern going one way, with another pattern going the opposite way.

Triangles: Unlike a grid pattern, which is usually placed horizontally and vertically, a triangle pattern uses printed lines that create a triangular pattern. The meeting points at which these triangles meet act as an extra support area for the pattern.

Hexagonal: Of the three most common standard infill patterns, hexagonal infill is one of the most supportive patterns. This is because of the way that a hexagonal infill pattern is printed; it takes up more space in the model or project you are working on. Thus, making it more filled and stronger.

Standard infill patterns are some of the most commonly used when it comes to 3D printing. Not only are they incredibly versatile, but in terms of cost and production time, they can fit into almost any budget. With most creators wanting around 20% infill for the average project, that percentage is easy to accomplish.

It is also worth noting that the triangle seems to be the most popular of the standard infill patterns. Most users prefer this pattern because it creates a full appearance in a model or project, but also because it provides a lot of strength without having to fill in an area completely.

Functional Infill Patterns

Suppose strength is your primary concern when 3D printing, then the functional infill patterns are going to be the best option for you. Although you are going to face higher costs and a longer timeline, you are less likely to have to replace any infill overtime. This is especially important if you are working on complicated or expensive projects.

Cubic: Sometimes referred to as the strongest 3D infill pattern available, it is also known as the honeycomb pattern. It uses stacked filament cubes to create a 3D shape and takes up a considerable amount of space in the model or project.

Cubic Subdivision: The cubic subdivision is similar to the standard cubic infill pattern but uses less product to achieve those results. This is an excellent option for those who are looking to reduce the amount of product or cost a project may have.

Octet: One of the more complicated patterns is the octet, which comprises an infill pattern mostly made from pyramids that have been stacked on top of each other.

Quarter Cubic: Quarter cubic is another pattern that is a variation of another functional pattern. This time it offsets the octet pattern while still using pyramids. This is a typical pattern for models or projects that may have exposed areas.

Gyroid: If you need an infill to provide support and extra strength to various sides of a model, then a gyroid infill pattern is your best option. It creates wave-like shapes across the model or project.

Due to high-density infill patterns, functional patterns are often left for high-level projects. Having almost entirely to fill in a model can become costly, and many of these patterns are quite intricate and require more time in printing as well as the need for more filament.

For those looking for the ultimate strength from their infill pattern, it is hard to go wrong with any of these. You should make sure that your project needs that amount of strength and support before investing in a more costly printing method. It may also be worth checking to see if your software and printer are even capable of these patterns.

Flexible Infill Patterns

The last category to consider in terms of the strength of different infill patterns is the flexible options. What makes the flexible patterns unique is that you can make them as strong as you need it to be based on the model or project you are working on. The following patterns are usually best suited to work with flexible filament materials.

Concentric: Although this pattern makes waves, it is different than a gyroid infill pattern. It creates waves that follow the shape of what you are working on to make it even stronger and provide additional support.

Cross: If you plan to move your project or model in quite a few different ways, then a cross pattern is perfect for providing support without sacrificing strength. It uses small cross-like patterns to fill in the area of the model.

Cross 3D: For 3D projects, a cross 3D is the strongest flexible inline pattern option. It is almost exactly the same as a cross pattern but moves vertically as it prints in order to fill in space and create a more stable pattern.

A lot of people consider flexible infill patterns to be a second thought. The three categories listed above are the most used and can be performed by almost any machine on the market. Unless you are creating a unique model, flexible patterns are not often considered.

What Infill Strength Percentage Do You Need?

One common theme with infill patterns is that they all have different infill percentages that tell you what kind of strength you can expect from them. Most projects also have a recommended or minimum strength percentage, which you can use as a guideline.

Here are the typical strength percentages for each category.

0-15%: Models and Figurines
15-50%: Standard
Over 50%: Functional
0-100%: Flexible

It is relatively easy to see the potential strength in each of the infill patterns listed above. The higher density or strength an item is, the more “filled-in” the area will appear. Infill percentage will also directly link to how “squishy” an item may be after production, regardless of the material you use.

You should also be aware of what an infill percentage can mean for your model. If you use an infill of 100%, that means that your model or project is going to be completely solid. There will be no additional room for twists or turns. Most infill patterns range anywhere between 20-40%.

Strength percentage only goes so far. This is especially important if you are using a denser or higher-quality filament. The higher the strength percentage your filament is, the more you may want to consider using less.

Once you get to a certain infill point, usually 50%, you typically do not see any increase in strength and may end up wasting materials.

What is the Quickest Infill Pattern?

Even though cubic or honeycomb is the strongest, there are also creators out there who are looking for the quickest infill pattern available. Cubic is considered a quick pattern for the strength and support it provides to the project you are working on.

Here are the quickest infill patterns to choose from:

Line
Zigzag
Grid

As you may expect, the quickest infill patterns are going to be simple designs or 2D designs. By choosing a line or a zigzag, you are able to finish your design much quicker. You also may end up using less filament, which can save on production costs. There are specific standard patterns that you can choose from as well.

It is essential to know that often times, you may be sacrificing quality or strength by choosing a fast infill pattern over another. Depending on the software and the printer you are using, there may also only be a minimal time difference.

What Are Some Factors to Consider When Choosing an Infill Pattern?

As with most projects, there are a few things that you need to take into consideration. Before you begin to select your infill pattern, you need to take a good look at the project you are working on. If your project is okay with a line infill, you don’t need a gyroid infill. Here are some additional factors to think about.

What You Are Making

As always, the most obvious factor to take in is what you are actually trying to create. If you are creating something that is purely decoration, it may not need to be filled in so much. If you are creating something that is going to be used, you may need support and the ability for your project to bend and flex.

The Budget for Your Project or Model

One of the most significant factors for many creators is what you are willing or able to spend? If cost is not a factor to you, then you will probably want to go for a honeycomb or a rectilinear pattern. Some additional factors that may influence the cost of your project are:

Simpler patterns will take less time to create and cost less.
You may be able to cut down on costs by choosing a quality filament.
If time is a factor, choose an infill pattern that requires less printing time.

Density Required

Like I mentioned, what kind of project are you working on? If you are building something like a model of your favorite spaceship, then you could most likely get by with a line or a zigzag infill pattern. If you are creating something more complicated, you are obviously going to need something that offers more support and strength.

Layer Height

Since most infill patterns utilize layers, the layer height of what you are creating may play a significant role. The more layers you use in a single model, the stronger that model is likely to be. Many people achieve smaller layers by narrowing the printer’s nozzle, but this does increase production time.

Quality of Filament

The quality of filament you choose for your infill pattern can also make a huge difference. If you are using a thicker or higher-quality filament, you may get away with a lower strength pattern. This will be able to save you time and money when it comes to production. Here are some of the best filaments for 3D printing.

PLA
ABS
Nylon 910
Polycarbonate

Orientation of Print

Something that is often overlooked is how you are setting up your model or project to be printed. On anything you are printing on, there are XY and Z directions. You should always try to print your filament out on the XY axis if you are looking to maximize your model’s strength.

Infill Setting

Unless you have been 3D printing for a while, you may have a setting that you are overlooking. Most printers and software sets have an option to choose either a gradient infill or a gradual infill. You can typically still use the pattern you have selected but choose how much you need. Here are the differences:

Gradient Infill: With this setting, you will see more infill towards the outer edges of the project you are working on. By doing this, you are receiving the same amount of support in the model, but you are actually going to end up using less filament on the same project.
Gradual Infill: A gradual infill fills in your project more towards the bottom as opposed to the top. If your project needs to be heavily supported in all areas, this may not be the best option. It will, however, help you fill out areas along the edges that may need more support.

Although they may be easy to confuse, it is essential that you know the difference between the two settings if that is something you are going to adjust on your printer. Not all models or projects need an adjustment from what you already have. You may also ruin a model by choosing the wrong infill setting.

Is There Any Way to Increase the Strength of an Infill Pattern?

Although you can adjust the strength of an infill pattern by merely selecting the best infill pattern for your needs, there are a few ways that you can also increase the overall strength of the project you are working on. Here are a few ways to increase the strength of your 3D printed project.

Avoid additional cooling methods that may compromise the integrity of your project or model.
Increase the diameter of the nozzle so that more pressure is applied to help the layers melt and bond together.
Opt for a rectilinear infill pattern, which can maximize the strength of your project as well as reduce material waste.
Make sure you are using thin layers of filament. This will ensure that your layers are thoroughly cooled and bonded together.

Depending on the software and machine you are using to achieve your printing results, you may also be able to use different infill patterns in the same project. You want to make sure that patterns you use together are able to flex and bend as needed.

Some creators have even passed ultimately on using infill patterns in their models or projects. You can significantly increase the strength of a particular item by increasing the perimeter shell of what you are working on. If you are creating something that is simply for display, this may be a good option for you to try.

Common Myths About Infill Patterns

Although 3D printing is nothing new, there are still quite a few myths surrounding the process. There are undoubtedly many myths surrounding the strongest infill pattern and what you actually need for your project. Here are some of the most common myths concerning infill patterns.

Any Infill Pattern Will Work for Any Project

Although a honeycomb or a rectilinear pattern may be the overall strongest infill pattern you can choose, it does not mean that it is the best option. Often, the flexibility you need in a project may not actually work with that type of pattern. You also could run into issues with how your model or project appears.

Speed Makes all of the Difference

While you may want to get your project filled so that you can move onto another step, it is not ideal to speed through the printing process. For more detailed or 3D designs, it is best if you actually slow down the printing speed to ensure that your design is complete and actually fills in the required area.

Any Printer Can Make Any Infill Pattern

Before you choose a specific type of infill pattern, you should make sure that you can actually make the infill pattern. Not all printers and software are able to make specific infill patterns. You can refer to your user manual or quick online search to see what infill patterns are available for your device.

Final Thoughts

Most of the time, I focus on what a project looks like from the outside, but what is on the inside counts even more. Choosing the best infill pattern for your task may seem overwhelming, especially with all of the options available in terms of filament as well as software and method.

Those who are used to 3D printing will tell you that a honeycomb or a rectilinear is the strongest. While this is true in terms of how dense and filled in a project may be, that does not necessarily mean it will give you the results you are looking for or even work at all with what you are working on.

Remember, the four main categories are:

Models and Figures (Weakest Strength)
Standard (Average Strength)
Functional (Highest Strength)
Flexible

There are additional factors such as the quality of the filament, the density needed, the type of project you are working on, and even the orientation at which you are printing, which can impact the outcome of your project. If you are able to, a trial with your selected pattern can save time and money in the long run.