Complete Guide to Make & Create STL Files for 3D Printing

In today’s world you have the power to turn your digital designs into real and this magic is made possible through 3D printing, a technology which turns your idea and imagination into reality. Now, the gap between your digital design and the 3D printer is a file format called STL. Knowing how to create and modify STL files is very important if you really want to turn your idea into reality. So, this article is your guide from choosing the right software to create STL’s to fixing them to preparing them for 3D printing. 

How Do You Make & Create STL Files for 3D Printing

To create STL files for 3D printing, start with a CAD software like TinkerCAD for beginners or Fusion 360 for more advanced designs. Sketch your design, then export it as an STL file then open this file in a slicer software like Cura, adjust your print settings like layer height and infill, then slice it to convert it into G-code. Now, you can send this file to your 3D printer and start printing.

Understanding STL files

What is STL?

STL  stands for Standard Tessellation Language or Stereolithography, It is the method to translate your digital designs into the physical world through 3D printing. When you create a 3D design on your computer, the STL file acts as a digital blueprint, holding all the important information about the shape, structure, and surface geometry of your design​​. It’s like the script for your 3D printer to follow, telling it exactly how to recreate your design layer by layer.

The Structure of STL Files

STL files represent the 3D geometry of your design using a mesh of triangles. Imagine wrapping your design with a net of triangles, each one flat, but together they form the complex shape of your design. This way, your 3D printer gets a clear instruction on how to replicate the design you’ve designed on your computer screen​.


CAD (Computer-Aided Design) software where you design your 3D model. Once your design is complete, the CAD software helps you export it as an STL file and when you export your design as an STL file, the software breaks down the smooth surfaces of your design into a mesh of triangles.

CAD Software to Create STL Files

The 3D printing journey always starts with the right software selection. Your choice of software will play an important role in converting your idea into a tangible reality or STL file. Let’s get into some software options for different skill levels:

Beginners options

TinkerCAD: It is a free browser-based CAD software perfect for beginners. Its simplicity makes it a great tool to start your 3D modeling and printing journey. But you will only be able to create some basic design and  it is not suitable for complex designs​.

SketchUp: It’s another web-based 3D modeling tool. Its user-friendly interface is easy for beginners, and it also has a large community of users with many tutorials and guides available on youtube. The free version is quite good but there’s also paid versions also which offer more features.

Intermediate Options

Fusion 360: I think it’s one of the best tools which I personally use to create some great complex 3D models. It’s a feature rich and easy to use software for Intermediate to advanced users looking to create comlex designs for 3D printing​. It’s a paid tool but if you’re a student you can get the student version for free by just providing your student Id for verification.

SelfCAD: It’s a little feature rich browser-based STL editor in comparison to TinkerCAD and Sketchup and it’s easy to use, ideal for sculpting, sketching and rendering. It comes with a user-friendly interface which makes it straightforward for beginners to navigate.

Advanced Options

SolidWorks: A highly functional and feature-rich software, It is ideal for those with a good knowledge of the basics of 3D modeling and looking to create more complex designs. Solidworks is widely used in industries for its powerful 3D CAD and CAE capabilities.

Blender: It’s a free open-source 3D modeling and rendering software which is good for small design firms or individual designers. It’s a very diverse CAD software which can be used to create designs and models for 3D printing, game development, and animation.

Step-by-Step Guide to Creating an STL File

1. Selecting the Software

  • Your first step is to choose a CAD (Computer-Aided Design) software. Depending on your expertise, you can go for user-friendly beginner options like TinkerCAD or SketchUp. If you are on an intermediate level can go Fusion 360 which can be a great choice. But if you’re an advanced user and want to create a more complex design then Solidworks is the best option for you.

2. Creating the 3D Model

  • Once you have selected the CAD software, it’s time to create your 3D model. You can use the tools given in the software to design your model. It will take some time to get comfortable with CAD software as it’s all about learning and the best way to learn is to experiment and design something new everyday.

3. Exporting Your Design as an STL File

  • Now that your design is ready and it’s time to export it as an STL file. This file format is the standard for exporting 3D models especially for 3D printing. In your CAD software, look for the export option then select .STL file format and then the software will then convert your 3D model into an STL file and save it in your chosen drive and folder.

4. Checking Your STL File (optional)

  • After exporting, it’s a good thing to check your STL file for any errors. You can use software like MeshMixer to inspect the STL file. It helps you to check the issues like disconnected surfaces or overlapping triangles then fix them if needed.

Understanding Slicer Software

A slicer software plays a very-very important role in 3D printing. It basically translates the 3D model files into instructions that your 3D printer can follow. The typical file formats supported by slicer software are STL, OBJ, and 3MF,etc. The slicer takes these files and converts them into G-code. It is a language that 3D printers understand. This G-code file contains all the instructions regarding how each layer should be printed, the location, and the speed of the print, among other parameters​ which are required to print a 3D model.

Here’s what a good slicer software looks like:-

  • Speed: A good slicer quickly converts your STL file into a Gcode.
  • Error Detection: They can flag errors in your file that can lead to printing issues.
  • User-Friendly Interface: As a hobbyist you always want a simple, user friendly interface and a smooth user experience.
  • Real-Time Data: A good slicer software provids data like total print time, filament requirement, filament cost etc.

Some Popular Slicer Software


Cura is one of the most popular open-source software in the 3D printing community. Cura has one of the most user-friendly interfaces and comes with a lot of  features. One of the best things about Cura is you can integrate with popular 3D printers and CAD software. In its latest update, version 5.4, Cura comes with enhanced tree supports and better brims which will help in easier removal post-print. 


On the other side, we have PrusaSlicer, another popular slicer software in the 3D printing community. This software is also open-source and is developed by the 3D printer manufacturer Prusa Research. PrusaSlicer comes with a very user-friendly interface and a lot of features. It’s the go-to software for many people, especially the one’s who own Prusa 3D printers. With its 2.6 update, PrusaSlicer came up with organic support, multi-tool slicing, etc..

Paid Slicer Software

  • Simplify3D
  • MatterControl
  • Netfabb:

Each of these slicer software options comes with its own set of advantages and features but you should choose according to  your project requirements, budget, and the level of expertise you have in 3D printing.

Using Slicer Software: A Step-by-Step Guide

1. Choose a Slicer

The First step is choosing the right slicer software that fits with your printer. Popular choices include Cura, PrusaSlicer, and for those who don’t mind spending a bit, Simplify3D is the best option.

2. Find and Design the 3D Model

Once you select the slicer software. Now, you need a 3D model to 3D print, either you can design it or you can download the 3D models from websites like Thingiverse, Printables or MyMiniFactory.

3. Adjust Slicer Settings

Now, it’s time to tinker with the slicer settings. You need to set important parameters like layer height, print speed, infill density percentage , Retraction,Cooling fan and temperature settings. Adjusting these settings is important as they directly influence your print quality and speed​. But slicers like Cura also have pre designed material and Printer and quality profiles presets and you dont have to tweak anything or just a few settings according to your need.

4. Slice and Preview Model

Once you are done with the settings you can click on the slice button to proceed with the slicing of the model into G-Code. This process translates your 3D model into layers, basically creating a roadmap for your printer. By clicking on the preview button you can see the sliced model.

5. Transfer and Print the File

After slicing into G-Code the model now it’s time to put that G-Code file in your 3D printer, either via SD card, USB, WIFI or ethernet connection then hit the print button and watch your creation come to life​.


Now, I hope you got a better idea of what slicer software is and  the importance of selecting the right print settings and the workings of STL files. We’ve gone through from the steps of creating a 3D model to slicing it to sending it for printing while also fixing some common issues that come the way. But remember every print gives you a lesson. So, keep experimenting with your print settings until you get the finest print quality your printer can print.


1. How do I create an STL file for beginners?

  • You can start with a user-friendly CAD software like TinkerCAD, sketch your design, then click on ‘Export’ and select ‘.STL’ file format to save your design as an STL file.

2. How are STL files generated?

  • STL files are generated by creating a 3D model in a CAD (Computer-Aided Design) software and then exporting the model in STL (Stereolithography) file format.

3. What app is used to make STL files for 3D printing?

  • Apps like TinkerCAD, Fusion 360, or SketchUp are popular among people for creating STL files for 3D printing.

4. How to convert a 3D model to STL?

  • In your CAD software, after completing your 3D model, look for the ‘Export’ or ‘Save As’ option in the menu, then select ‘STL’ as the file format then Click on export buttion, and your 3D model will be saved as an STL file in the selected folder and drive.

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