Do 3D Printers Only Print Plastic? What Do 3D Printers Use for Ink?

3D printing is versatile, but people wonder whether 3D printers only print plastic. This article will look into what kind of materials 3D printers can use.

Consumer 3D printers mainly use plastic like PLA, ABS or PETG which are known as thermoplastics since they soften and harden depending on the temperature. There are many other materials you can 3D print with different 3D printing technologies like SLS or DMLS for metals. You can even 3D print concrete and wax.

There’s some more useful information that I’ve put in this article about the materials that are used in 3D printing, so keep reading for more.

What Do 3D Printers Use for Ink?

If you have ever wondered about what 3D printers use for ink, here’s the simple answer to that. 3D printers use three basic types of materials for ink which are namely;

Thermoplastics (filament)
Resin
Powders

These materials make use of different types of 3D printers to print, and we are going to take a look at each of these materials as we proceed.

Thermoplastics (Filament)

Thermoplastics are a type of polymer that becomes pliable or moldable when heated to a particular temperature and hardens when cooled.

When it comes to 3D printing, filaments or thermoplastics are what 3D printers use for “ink” or material to create 3D objects. It’s used with a technology called Fused Deposition Modeling or FDM 3D printing.

It’s probably the simplest type of 3D printing out there since it doesn’t require a complex process, rather just a heating of filament.

The most popular filament that most people use is PLA or Polylactic Acid. The next few most popular filaments are ABS, PETG, TPU & Nylon.

You can get all sorts of filament types as well as different hybrids and colors, so there really is a wide range of thermoplastics you can 3D print with.

An example would be this SainSmart Black ePA-CF Carbon Fiber Filled Nylon Filament from Amazon.

Some filaments are harder to print than others, and have very different properties which you can choose according to your project.

3D printing with thermoplastic filaments involves the material being fed through a tube mechanically with an extruder, which then feeds into a heating chamber called the hotend.

The hotend is heated to a temperature at which the filament softens and can be extruded through a small hole in a nozzle, usually 0.4mm in diameter.

Your 3D printer operates on instructions called a G-Code file that tells the 3D printer exactly what temperature to be at, where to move the print head, what level the cooling fans should be at and every other instruction that makes the 3D printer do things.

G-Code files are created through processing an STL file, which you can easily download from a website like Thingiverse. The processing software is called a slicer, the most popular one for FDM printing being Cura.

Here’s a short video that shows the filament 3D printing process from start to finish.

I actually wrote a full post called the Ultimate 3D Printing Filament & Materials Guide that takes you through several types of filaments and 3D printing materials.

Resin

The next set of “ink” that 3D printers use is a material called photopolymer resin, which is a thermoset liquid that is light-sensitive and solidifies when exposed to certain UV light wavelengths (405nm).

These resins are different to epoxy resins which are usually used for hobby crafts and similar projects.

3D printing resins are used in a 3D printing technology called SLA or Stereolithography. This method provides users with a much higher level of detail and resolution due to how each layer is formed.

Common 3D printing resins are Standard resin, Rapid resin, ABS-Like resin, Flexible resin, Water Washable resin, and Tough resin.

I wrote a more in-depth post about What Types of Resin Are There For 3D Printing? Best Brands & Types, so feel free to check that out for more details.

Here is the process for how SLA 3D printers work:

Once the 3D printer is assembled, you pour the resin into the resin vat – a container that holds your resin above the LCD screen.
The build plate lowers into the resin vat and creates a connection with the layer of film in the resin vat
The 3D printing file you are creating will send instructions to light up a specific image that will create the layer
This layer of light will harden the resin
The build plate then raises up and creates a suction pressure which peels off the created layer off the resin vat film and sticks to the build plate.
It will continue to create each layer by exposing a light image until the 3D object is created.

Essentially, SLA 3D prints are created upside down.

SLA 3D printers can create amazing details due to being able to have resolutions of up to 0.01mm or 10 microns, but the standard resolution is usually 0.05mm or 50 microns.

FDM 3D printers usually have a standard resolution of 0.2mm, but some high-grade machines can reach 0.05mm.

Safety is important when it comes to resin because it has a toxicity when it comes into contact with skin. You should use nitrile gloves when handling resin to avoid skin contact.

Resin 3D printing does have a longer process due to the necessary post-processing. You need to wash the uncured resin off, clean up the supports that are requires to 3D print resin models, then cure the part with an external UV light to harden the 3D printed object.

Powders

A less common but growing industry in 3D printing is using powders as “ink”.

Powders used in 3D printing can be polymers or even metals that are reduced to fine particles. The qualities of the metal powder used, and the printing process determines the outcome of the print.

There are several types of powders that can be used in 3D printing such as nylon, stainless steel, aluminum, iron, titanium, cobalt chrome, among many others.

A website called Inoxia sells many types of metal powders.

There are also different techniques that can be used in 3D printing with powder such as SLS (Selective Laser Sintering), EBM (Electron Beam Melting), Binder Jetting & BPE (Bound Powder Extrusion).

The most popular is the sintering technique known as the Selective Laser Sintering (SLS).

The process of Selective Laser Sintering is done by the following:

The powder reservoir is filled with a thermoplastic powder typically nylon (round and smooth particles)
A powder spreader (a blade or roller) spreads out the powder to create a thin and uniform layer on the build platform
The laser selectively heats up parts of the build area to melt the powder in a defined manner
The build plate moves down with each layer, where the powder gets spread out again for another sintering from the laser
This process is repeated until your part is completed
Your final print will be encased in a nylon-powdered shell which can be removed with a brush
You can then use a special system that uses something like high-powered air to clean the rest of it off

Here is a quick video on what the SLS process looks like.

The process is done by sintering the powder to form solid parts that are more porous than the melting point. This means that the powder particles are heated so that the surfaces weld together. One advantage of this is that it can combine materials with plastics to produce 3D prints.

You can 3D print with metal powders using technologies like DMLS, SLM & EBM.

Can 3D Printers Only Print Plastic?

Although plastic is the most common material used in 3D printing, 3D printers can print materials other than plastic.

Other materials that can be used in 3D printing include:

Resin
Powder (polymers & metals)
Graphite
Carbon Fiber
Titanium
Aluminum
Silver and Gold
Chocolate
Stem cells
Iron
Wood
Wax
Concrete

For FDM printers, only some of these materials can be heated and softened rather than burned so that it can be pushed out of a hotend. There are many 3D printing technologies out there that expand the material capabilities of what people can create.

The main one is the SLS 3D printers that make use of powder with the laser sintering technique to make 3D prints.

Resin 3D printers are also commonly used for home and commercial purposes. This involves using the photopolymerization process to solidify liquid resin with UV light which then passes through post-processing for a high quality finish.

3D printers can not only print plastic but can print other materials depending on the type of 3D printer in question. If you want to print any of the other listed materials above, you should get the relevant 3D printing technology to print.

Can 3D Printers Print Any Material?

Materials that can be softened and extruded through a nozzle, or powdered metals can be binded together to form an object. As long as the material can be layered or stacks on top of each other it can be 3D printed, but many objects don’t fit these characteristics. Concrete can be 3D printed since it starts off soft.

3D printed houses are made from concrete that gets mixed up and extruded through a very large nozzle, and hardens after some time.

Over time, 3D printing has introduced plenty of new materials such as concrete, wax, chocolate, and even biological matter like stem cells.

Here’s what a 3D printed house looks like.

Can You 3D Print Money?

No, you can not 3D print money due to the manufacturing process of 3D printing, as well as the embedded markings on money that make it anti-counterfeit. 3D printers mainly create plastic objects using materials like PLA or ABS, and definitely can’t 3D print using paper. It’s possible to 3D print prop metal coins.

Money is made with a lot of markings and embedded threads that a 3D printer may not be able to accurately reproduce. Even if a 3D printer can be able to produce what looks like money, the prints can not be used as money as they don’t have the unique qualities that make up a bill.

Money is printed on paper and most 3D prints are printed in plastic, or solidified resin. These materials cannot function the way a paper would and cannot be handled the same way one would be able to handle money.

Research shows that the modern currency of most countries in the world has at least 6 different technologies built into them. No 3D printer will be able to support more than one or two of these methods that are required to accurately print the bill.

Most countries especially the US are building bills that incorporate the latest high-end tech anti-counterfeiting features which will make it difficult for a 3D printer to print them. This can only be possible if the 3D printer has the required technology to print the concerned bill.

A 3D printer can only try to print a look-alike of money and does not have the right technology or materials to print money.

Many people create prop coins using a plastic material like PLA, then spray-painting it with a metallic paint.

Others mention a technique where you can create a 3D mold and use precious metal clays. You would press the clay into form then fire it into metal.

Here’s a YouTuber who created a D&D coin that has “Yes” & “No” on each end. He made a simple design in a CAD software then created a script where the 3D printed coin pauses so he could insert a washer inside to make it heavier, then finishes off the rest of the coin.