Categories: Basics

Beginners Guide to 3D Printing Infill – Learn the Basics


What is 3D Printing Infill?

3D Printing Infill is an important print setting that impacts the strength, weight, and structure of the print.  In the simplest of definitions, infill is a repeating internal structure that is built up inside a 3D print. Although the main purpose of Infill is to provide rigidity to the print, it can also serve to adjust the weight of the print. This is altered by modifying the Density setting of the 3D printing infill.

3D Printing Infill Density

Infill Density is a slicer setting which allows you to specify how much infill you want inside your print. Typically Infill Density is specified as a percentage. A value of 0% indicates a 3D print that is completely hollow inside, where a value of 100% indicated a 3D print that is completely solid inside. The exact Infill Density you select is very dependent on the application of the print, although 10-30% is common and typically sufficient for most applications. A model which will have no loading can use a lower infill percentage (10-15%), while a part which will provide structure will need a high infill percentage (15-30%). Infill percentages of 30% or greater are common for parts with higher loadings which require additional strength. Of course adding more infill percentage will increase the overall weight of the 3D print and consume more filament ($). That being said, in many cases additional weight is actually desired to give the part a higher quality feel.

3D Printing Infill Styles

There are many styles of infills to choose from. The style of infill can impact the strength, print time, and flexibility in the final 3D print.

Infill Selection Considerations

Here are some general guidelines on which type of infill to use for different applications. Of course, you should evaluate the specific needs of your 3D print to decide which style is the best option for your print.

Strength Priority: Grid, Triangles, Tri-Hexagon, Cubic, Cubic (Sub), Octet, Quarter Cubic

Speed (Print Time) Priority: Lines, Zig-Zag

Flexibility Priority: Concentric, Cross, Cross 3D

Here is another great article on 3D printing infill.


As with most things with 3D printing, one of the best ways to determine the infill percentage and style best for your application is to use the trial-and-error approach. Using the guidelines above will help you choose a starting point, but try it out and see what works best for your application!

Click here to learn more about other Slicer settings and how they impact your 3D print.

This post was published on June 29, 2019

The 3D Print Zone
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