Infill vs Shell in 3D Printing: What’s the Difference?


When researching 3D printing, you’ll probably encounter some otherwise confusing terms, including infill and shell. 3D printing is a complex manufacturing technique. Although there are a variety of 3D printing processes, they all involve building three-dimensional objects from a computer-generated file. Infill and shell are two key components of 3D printing processes. They provide the structure for printed objects, making them essential for all 3D printing process. What’s the difference between infill and shell in 3D printing exactly?

What Is Infill?

Infill is the deposited material that encompasses the center of a printed object. Depending on the specific type of 3D printing process, as well as the 3D printer itself, manufacturing companies may be able to adjust the infill. In other words, they can specify the percentage of infill used to build the object. An infill of 100% means the printed object will be completely solid, whereas an infill of 0% means the printed object will be completely hollow.

Infill acts as the stuffing for printed objects. All objects are built using raw material, which is generally released out of the 3D printer’s nozzle. The raw material that encompasses the center of a printed object is known as infill.

What is Shell?

Shell, on the other hand, is the deposited material that encompasses the outside of a printed object. It’s called “shell” because it acts like a shell or casing for printed objects. Printed objects contain a shell, and within the shell is infill. Both shell and infill are usually comprised of the same raw material.

Going back to the basics of 3D printing 101, this additive manufacturing technique involves building objects layer by layer. 3D printers deposit raw material in layers. They’ll build the first layer at the bottom, after which they’ll build the next-highest layer directly on top of it. 3D printers will continue this cycle until they’ve built all the layers as indicated in the computer-generated file. Shell is simply the perimeter of each layer. Like infill, shell can typically be customized. 3D printers support control options that allow manufacturing companies to adjust the shell used in their printed objects.

In Conclusion

Infill and shell consist of raw material that create 3D printed objects. 3D printers must deposit raw material — typically layer by layer — to build objects. Infill is the raw material that’s deposited in the center of a printed object, whereas shell is the raw material that’s deposited on the outside or perimeter of a printed object.

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