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Just How Fragile Are 3D Prints? The Facts Explained

Depending on the size and subject, you're either paying affordable prices or mind-blowingly hefty prices for a piece of 3D art. But just how fragile are 3D prints?

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3D prints have become more and more popular over the years, and if you’ve ever looked on websites such as Etsy, you’ll see people selling 3D prints of just about anything. Depending on the size and subject, you’re either paying affordable prices or mind-blowingly hefty prices for a piece of 3D art. But just how fragile are 3D prints?

3D prints are not fragile, provided you have a solid design with appropriate wall thickness and amount of infill. Still, the more detailed the design, the more likely it is to break. The type of filament used can also affect a print’s fragility, so PLA or PC are advised for the most durable prints.

This article will explain how to ensure the strength of your 3D prints and discuss the issues that can affect their fragility. 

What Makes 3D Prints Fragile

3d printing can be a long process, with some prints taking more than a day to complete. With that in mind, no matter what you’re printing, you want to be sure that it’s going to last.

3D printed objects are generally quite robust, but if you don’t ensure the walls are thick enough or add the right amount of infill – or any infill at all – you might find your final print is quite fragile.

And if you have a design with small, delicate pieces, it will be more likely to break than something solid. 

Luckily, it’s easy to modify print files to ensure its quality.

Let’s go over a few ways that will affect the fragility of your piece:

Using the Wrong Type of Filament

The first step of making anything is deciding what materials you’ll use. If you’ve ever watched an episode of Project Runway, you’ll know that for some designers, their first mistake was picking the wrong fabric for their garment. 

The same applies to 3D printing- the right or wrong material can either make or break your whole project.

The materials you use are dependent on the type of project you’re creating. When choosing the suitable material for your project, you need to consider these factors:

  • Do I need this project to be impact-resistant?
  • Do I need this project to be chemically resistant?
  • Should any part of this project be flexible or rigid?
  • Does my project need to be heat or water-resistant?

According to, the strength of 3D printed parts is relative to their function, and the material you choose should reflect this. 


Polycarbonate (PC) is considered one of the most robust materials available for 3D printing (not including resin). 

It has some of the best thermal and impact resistance, and tests have shown that it can handle over twice the weight of PLA.

However, it doesn’t print as well or as smoothly as other filaments and can’t handle smaller, more delicate pieces as well.

Still, PC prints are far less likely to be fragile, so it’s a good choice if you’re making simple designs. 


PLA (Polylactic Acid) is one of the most popular filaments available, and it generally makes quite robust parts. For hobbyists, it typically has more than enough strength. 

That said, if you’re creating a heavier weighted project, you’ll want to avoid using PLA. 

Though it’s one of the more readily available material choices for 3D printing, it can become brittle when bearing heavy loads, meaning your heavier projects will fall apart after some time. 

The good news is it’s biodegradable, so if your project does fall apart, at least it won’t negatively impact your carbon footprint!

Nylon and Polycarbonate

Materials like Nylon are suitable for projects that need more flexibility, like hinges or parts for a cosplay costume. 

Polycarbonate’s common use is in manufacturing bullet-proof glass, so it has excellent dimensional stability and is ideal for high-strength and functional projects.

Using a Poor Quality 3D Printer

There are many printers on the market today, and the quality of the machine can affect how fragile your print comes out.

For example, suppose you buy a second-hand printer that’s never had a nozzle change or any maintenance done in the years it’s been used. Chances are, the print you see won’t be up to the same standard as a new Ender Pro. 

Similarly, if the print bed is worn or the fan is not in proper working order, you might see filament stringing or not adhering to the bed at all. 

Of course, different 3D printers are more suitable than others for various projects. There are eight different types of 3D printers meant for multiple projects. 

Here’s a brief rundown of those eight types:

  • Digital Light Process (DLP)
  • Direct Metal Laser Sintering (DMLS)
  • Electron Beam Melting (EBM)
  • Fused Deposition Modeling (FDM)
  • Multi Jet Fusion (MJF)
  • PolyJet
  • Selective Laser Sintering (SLS)
  • Stereolithography (SLA)

Fused Deposition Modeling (FDM) is one of the cheapest and most-used 3D printers, especially for hobbyists. Luckily, they’re available for just a few hundred dollars brand new, which should maintain your prints’ quality for longer.

Using the Wrong Cooling Settings

3D printing works by layering melted filament. The nozzle traces the outline of the design and then moves over and over, building the print up from the bed until the model is finished.

The key to this process being successful is having a good bond between the layers. 

So, if the first layer cools too quickly, the second layer may not adhere correctly. Then, if the second layer cools, the third layer may not stick, and so on.

You’ll likely be left with a fragile piece if this continues throughout the print. This is because the layers aren’t fused together as they should be.

Adjust the cooling settings or turn the fan off completely to fix this.

Using Low Infill or Print Density

Without the right level of infill and print density, your model will likely be quite fragile. So, to make the print stronger, increase the interior density in your chosen slicing program. 

For example, if the infill is set to 20%, increase it to 50%. This will add over twice the interior layers, making your print more durable. 

Another option would be to use a honeycomb infill design, which is incredibly strong. 

Keep in mind, though, that not all prints will need heavy infills. For example, if the finished product is a small trinket, having 100% infill destiny would be overkill.

Instead, choose a percentage that matches the print’s needs. 

Incorrectly Storing Filament

Certain filament materials, such as PLA are hygroscopic, meaning they absorb water and moisture. If this happens, the filament can and often will expand and become distorted.

If it absorbs too much moisture, for example, when left out in a humid room, it may crack, bubble, or become stringy when extruded. This will prevent it from adhering correctly to the print bed and keep the layers from bonding.

So, to maintain the quality of the filament and, therefore, the finished print, you should always store the filament in an airtight container. 

If you think that the filament has been exposed to moisture, dry it out in the oven:

  1. Set the oven to its lowest temperature.
  2. Put the filament on the middle rack.
  3. Leave to dry for 4-6 hours.
  4. When cool, store with silica gel in an airtight container.


The fragility of your 3D print lies in the materials and printer you use. With the right combination of materials plus the 3D printer, you can create projects that’ll be long-lasting, strong, and durable. 

So do your research, make some prototypes, and don’t be afraid to experiment with several materials until you find one that fits your project best.

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About Ben

I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.