Blender- Smoothing STL files

Blender- Smoothing STL files with Blender for 3D printing


This is a tutorial for using the free, but powerful, software Blender (download available here: Blender downloads) to add additional polygons to STLs created in SketchUp. Doing this will create higher quality models out of your STL file, allowing for higher quality prints.


Blender is a powerful open-source tool used for 2D and 3D graphics, full-on animations, sculpting, rendering, compositing, motion tracking, game creation, and more. One of its many features is the ability to manage and edit STL files, which are commonly used in 3D printing. Smoothing STL files is essential because it ensures that the 3D printed object will have a refined and professional finish. Rough or jagged edges can not only affect the aesthetics of the printed object but can also impact its functionality.  (download available here: Blender downloads)

Step-by-Step Guide:

To achieve the best results when smoothing STL files in Blender, follow this guide. (Note: Ideally, this section would be accompanied by screenshots or video tutorials for a more comprehensive understanding.)

  1. Import the STL File: Open Blender and go to File > Import > Stl (.stl). Navigate to your STL file and click “Import STL”.
  2. Enter Edit Mode: With the object selected, switch to Edit Mode.
  3. Select All Vertices: Press A to select all vertices.
  4. Apply Smooth: Go to the left toolbar and under the “Shading” tab, choose “Smooth”.
  5. Modifiers: For further smoothing, you can apply a “Subdivision Surface” modifier.
  6. Export the Smoothed STL: Once satisfied with the smoothing, go to File > Export > Stl (.stl) to save your smoothed object.

Tips and Tricks:

  • Save Frequently: Blender doesn’t auto-save by default. Ensure you save your progress frequently.
  • Use the Sculpt Mode: For more intricate smoothing, consider using the sculpt mode in Blender.
  • Adjusting Smoothness: The “Subdivision Surface” modifier has a “View” and “Render” value. Increasing these values will increase the smoothness.
  • Next Level Smoothness:  Looking to achieve a sleek, smooth finish on your real-life ABS parts? Dive into our guide, “7 Steps to a Shiny Porcelain Finish on ABS Parts with Acetone”, and discover the simplicity of attaining that glossy shine.


  • Adhesion: Tired of parts not adhering properly to the printer bed? Ensure flawless bed adhesion with any filament using our specialized 3D printer bed adhesive, Wolfbite, and say goodbye to detachment issues. 

FAQ Section:

  • Q: Why are my STL files rough after exporting from a design software?
    A: STL files represent surfaces as a mesh of tiny triangles. The smaller and more numerous the triangles, the smoother the surface. However, some design software may export STLs with larger, fewer triangles, leading to a rougher appearance.

  • Q: Can I smooth only a part of my STL file in Blender?
    A: Yes, in Edit Mode, you can select specific vertices, edges, or faces and apply smoothing only to the selected areas.

  • Q: Does smoothing increase the file size of my STL?
    A: Yes, smoothing can increase the number of vertices and triangles in the mesh, leading to a larger file size.




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