What Is 3D Printing?

How 3D printers work and how to use them

3D printing is a manufacturing process where you create a three-dimensional, physical object from a digital file. This process is known as "additive manufacturing," meaning that material is added, not removed.

With 3D printing, you create a 3D digital design in a modeling program, known as CAD software, and then use a 3D printer to produce layers of material to form the finished object. Businesses, researchers, hobbyists, medical professionals, and more use 3D printing for a wide range of applications.

Here's a look at how 3D printing came to be, how it works, what it's used for, and what the future holds for this technology.

3D printing might be part of your favorite movie. Props in movies such as Black Panther, Iron Man, The Avengers, and even Star Wars make use of 3D printing, allowing set designers to create and recreate props easily and inexpensively.

3D Printer producing latice structure vase
 Marco Vacca / Getty Images

The History of 3D Printing

3D printing is older than you might think. In the early 1980s, 3D printing technology appeared, but it was known as "rapid prototyping technology," or RP. In 1980, Dr. Kodama of Japan filed a patent application for RP technology, but the process wasn't completed.

In 1984, Charles "Chuck" Hull invented a process he called stereolithography, which used UV light to solidify material and create a 3D object layer by layer. In 1986, Hull was issued a patent for his "stereolithography apparatus," or SLA machine.

Chuck Hull went on to form 3D Systems Corporation, one of the biggest 3D tech companies in the world.

Other 3D printing processes and technologies were being developed around the same time, and further enhancements continued throughout the '90s and early 2000s. Still, the primary focus of 3D printing technology was prototyping and industrial applications.

3D printing technology started to get noticed by the mainstream media in 2000 when the first 3D-printed kidney was created, though successful transplantation of a 3D kidney didn't happen until 2013. In 2004, the "RepRap Project" had a 3D printer print out another 3D printer, and still more media attention was drawn in 2008 with the first 3D printed prosthetic limb.

Other 3D advances rapidly followed, including a 3D printed house a family moved into in 2018.

Today, 3D printing isn't just about prototypes and industrial manufacturing. Hobbyists, scientists, and everyone in between use 3D printing for product manufacturing, consumer goods, medical advances, educational materials, and much more.

4D printing is on its way, as well, with printed objects that can change their shape over time.

How 3D Printers Work

There are several types of 3D printing technologies, including Fused Deposition Modeling (FDM), also known as Fused Filament Fabrication (FFF). FDM is the most common and popular method, used in most affordable 3D printers.

The FDM printing method uses a filament of plastic material, a bit like a string. The filament is fed from a roll into a heated head, which melts the plastic. To start producing a part, the head extrudes melted plastic onto the bed of the machine. The head moves over the bed, in 2D, depositing the first layer of material.

Once the first layer is complete, the head is moved up by the thickness of the first layer, and it starts depositing the next layer on top. The part is built up layer-by-layer, kind of like baking a loaf of bread slice by slice.

Popular FDM 3D printers include MakerBot and Ultimaker.

Diagram showing how an FDM 3D Printer works, see caption for details

Example of How to Use a 3D Printer

Here's a look at how simple 3D printing might work on an FDM printer.

  1. Download a 3D model you want to print, or design one yourself.

    Find downloadable models on Thingiverse or GrabCAD. To design a model yourself, try SketchUp or Blender. For engineering parts, try CAD software such as SolidWorks.

  2. If it isn't already, convert your model into a 3D printing format, such as an STL file.

  3. Import your model into slicing software, such as MakerWare, Cura, or Simplify 3D.

    MakerWare works with MakerBot 3D Printers. Cura and Simplify 3D produce G-code, which works with most 3D printers.

  4. Configure the build in your slicing software. Decide how to orientate your model on the 3D printer. For FDM, you want to minimize overhangs steeper than 45 degrees, since these will require support structures.

    When deciding on the orientation, consider how the model will be loaded so layers won't separate easily.

    3D Printing Support Structures
    Marina Skoropadskaya / Getty Images

    To save time and materials, models are generally not solid. Specify the infill percentage (typically 10-35 percent), the number of perimeter layers (typically 1-2), and the number of bottom and top layers (typically 2-4). There are many other things to consider when preparing your model for 3D printing.

  5. Export the program, which is typically a G-code file. Your slicing software will convert your model, and the build configuration you specified, into a set of instructions. Your 3D printer will follow this to build the part.

  6. Transfer the program to your 3D printer using an SD card, USB, or Wi-Fi.

  7. Print the model on your 3D printer.

    Woman watching 3D Printer build a part
    vgajic / Getty Images
  8. When the 3D printer has finished building your model, you'll need to remove it and possibly also clean it. Break off any support structures and rub off any remaining lumps with fine sandpaper.

Other Types of 3D Printing Machines

Other than FDM printers, 3D printing methods also include stereolithography (SLA), Digital Light Processing (DLP), selective Laser Sintering (SLS), Selective Laser Melting (SLM), Laminated Object Manufacturing (LOM), and Digital Beam Melting (EBM).

SLA is the oldest 3D printing technology and is still in use today. DLP uses lighting as well as polymers, while SLS uses a laser as a power supply to create strong 3D printed objects. SLM, LOM, and EBM have largely fallen out of favor.

The Future of 3D Printing

Will 3D printing lead us to a future of on-demand, customized products instantly made to our exact specifications? While this remains unclear, 3D printing technology is growing rapidly and being used in many areas of life.

3D printing of houses, body organs such as kidneys and limbs, and other advances have the potential to improve the lives of untold people around the world.