3D Printing: Fundamentals and How It Works

Lisa Ernst · 09.11.2025 · Technology · 4 min

3D printing may sound like science fiction to many, but millions of desktop 3D printers are already in use in home workshops, offices and schools. This article provides an introduction to the world of 3D printing.

Quelle: Custom Representation

Fundamentals of 3D Printing

3D printing is a process in which an object is built layer by layer, instead of being milled from a block. It is also referred to as Additive Manufacturing. . For 3D printing you need a digital 3D model, a 3D printer and material, usually plastic filament or liquid resin. The printer virtually slices the digital model into thin layers and builds it back up physically layer by layer.

The most common technology: FDM (Fused Deposition Modeling)

For beginners it is FDM (Fused Deposition Modeling) the most relevant technology. FDM printers are the most widely used 3D printers worldwide, as they are inexpensive and relatively easy to use.

How FDM works:

• A roll of filament (e.g., PLA) is loaded.
• The filament is heated in a nozzle until it becomes soft.
• The nozzle moves over the print bed and lays down the first layer.
• The print bed lowers (or the print head moves up), and the next layer is deposited.
• In the end, a solid 3D object is produced.

An FDM printer can be understood as a precise, automated hot glue gun.

Quelle: 3d-drucker-test.eu

Building an FDM 3D printer: Here are the essential components of an Ultimaker 2.

Other printing methods in brief

• SLA / DLP / MSLA (Resin-Druck): . In this method, liquid resin is cured with light. Advantages include extremely fine details, ideal for miniatures and figures. Disadvantages include handling resin, post-processing with alcohol and UV light, as well as odor. (Formlabs)
• SLS / MJF (Pulverdruck): Powder (plastic or metal) is fused with a laser or heat. These processes are more in the industrial and professional sector. (Sinterit 3D Drucker und Zubehör)

For the typical home setup, FDM remains the preferred choice.

What materials are available?

For starters, two materials are particularly relevant:

• PLA: A biobased plastic, often made from corn starch. It is very easy to print and is ideal for figures, decorations, mounts and prototypes.
• PETG: A bit tougher and more temperature-resistant than PLA. Well suited for parts that must withstand stresses, such as outdoor mounts.

Other materials such as ABS or TPU (flexible) are available, but with PLA most beginner projects can be completed. (weerg.com)

Getting started with 3D printing

To get started with 3D printing, you'll need a few basics:

1. A beginner 3D printer (FDM)

Typical features of entry-level models are:

• Print volume of about 220 × 220 × 250 mm.
• Open frame design or semi-open enclosure.
• Automatic or semi-automatic bed leveling. Support for PLA, often also PETG. (3DJake Schweiz)

2. Filament (PLA)

One spool of PLA filament is enough for many small projects. Later you can try different colors and materials.

3. Slicer software

The slicer is a program that translates the 3D model into layers and print commands (G-code). Well-known examples are Cura, PrusaSlicer and Bambu Studio.

4. 3D models

There are platforms with free 3D models (e.g., pen holders, spare parts, figures). Models can be downloaded as STL files and printed directly.

Typical workflow – from the model to the finished part

The process from the digital model to the physical object includes several steps:

1. Obtain or create model: The file is usually in .stl or .3mf format.
2. Load into the slicer: Choose printer and material (e.g., PLA), set resolution/quality.
3. Slice and save G-code: The slicer computes the layers and generates the G-code.
4. Load onto the printer: This is done via SD card, USB stick or network, depending on the device.
5. Start print: The bed and nozzle heat up, filament is loaded, the print starts.
6. Post-processing: Remove any support structures, and, if needed, sand, paint, or assemble.

Quelle: darc.de

The 3D printing process: From idea to finished object.

Limits and Applications

Although 3D printing offers many possibilities, there are also limits that should be considered.

Where do the limits lie?

3D printing is not magic and has its quirks:

• Duration: Larger prints can take 6–12 hours or longer.
• Surface: On FDM printers, the layers are often visible, especially on curved shapes. (Formlabs)
• Mechanical & Maintenance: Nozzles can become clogged, the print bed must be leveled, and belts must be tensioned.
• Construction: For very specialized parts, it becomes necessary to design them yourself in CAD.

What can you use 3D printing for?

The applications of 3D printing are diverse:

• Phone or controller holder
• Organizer for desk or workshop
• Replacement parts (clips, mounts, buttons)
• Miniatures & Figures
• Enclosures for electronics projects
• Learning models (e.g., molecules, anatomy, architecture)

Many companies also use 3D printing for prototyping and, in some cases, even for mass production. (Wikipedia)

Quelle: user-added

Building an FDM 3D printer: Here are the essential components of an Ultimaker 2.

Conclusion for Beginners

If you enjoy tinkering and problem-solving, and want to design your own things, then 3D printing is an exciting option. It requires a certain learning curve, but thanks to affordable entry-level devices and a large community, getting started is easier than ever.