3D Printer Filament Guide
By Justin Cuellar, Senior Engineer
We’ve all been there. You’ve just finished designing a perfect part, you open up your slicer, and then you stare at your wall of filament spools. Will standard PLA melt if I leave this in my car? Will PETG snap if I drop it? Do I really have the setup to print Nylon Carbon Fiber?
Choosing the right 3D printing filament type is often the difference between a part that lasts for years and one that shatters the moment you put it under load. With the recent explosion of ultra-fast CoreXY printers and accessible composite materials, picking the right plastic is more overwhelming than ever. Whether you're a beginner just unboxing your first high-speed printer or an expert dialing in an industrial machine for aerospace parts, understanding the messy reality of material properties can be a superpower.
In this guide, we're cutting through the marketing fluff. We'll break down the most popular 3D printing materials—including the newest high-speed and carbon fiber blends—translate the engineering jargon into plain English, and give you the exact specs you need to pick the perfect material.
Mechanics of Materials: Decoding the Specs
Before we dive into the specific plastics, we need to talk about how we measure them. Unless you have a background in engineering, material data sheets can look like a wall of random numbers. Here is what those numbers actually mean for your 3D prints:
- Tensile Strength (Ultimate Tensile Strength): This is the ability of a material to resist being pulled apart without breaking or yielding (meaning it starts to permanently stretch/elongate, so the part deforms and won’t return to its original shape). If you hang weights from a printed hook, tensile strength dictates how much weight it holds before it snaps.
- Tensile Modulus (Stiffness): Stiffness is a material's resistance to bending or deforming under stress. A material with a high modulus is very rigid. Materials with low stiffness tend to have greater impact resistance (toughness) because they can absorb energy by flexing.
- Tensile Elongation at Failure: Also known as fracture strain, this is how much the material stretches before it breaks. It’s closely related to a plastic’s ability to take an impact without cracking.
- Max Service Temperature: The highest temperature a material can withstand for prolonged periods before its strength drops sharply and it begins to soften or deform.
A common mistake is asking for the "strongest" filament when you actually need the "toughest." A glass window is incredibly strong (high tensile strength/stiffness), but it will shatter if you hit it with a hammer (low toughness). Rubber is weak (low strength), but very tough. If your part needs to survive impacts or drops, look at Elongation and lower Stiffness, not just Tensile Strength.
Beginner Filament: The Daily Drivers
If you are new to 3D printing, or just need reliable, low-hassle parts, these are your best friends. They don't require expensive printer upgrades, heated chambers, or specialized build plates.
Standard PLA & High-Speed (Rapid) PLA
PLA (Polylactic Acid) is the undisputed king of consumer 3D printing. It is incredibly easy to print, requires no enclosure, and has a very low odor. It excels at high-detail prints and produces almost zero stringing. Recently, High-Speed (or Hyper/Rapid) PLA has hit the market to keep up with printers capable of 500mm/s+. These blends melt faster and flow better at high volumetric rates without losing extrusion consistency. However, all PLA is brittle and has a very low maximum service temperature. If you print a car dashboard mount out of PLA, it will turn into a puddle on the first sunny summer day.
PETG (Polyethylene Terephthalate Glycol)
PETG is the stepping stone into functional parts. It offers a fantastic balance of ease-of-use and durability. It’s slightly softer than PLA, giving it better impact resistance, and it can survive much higher temperatures. It's excellent for mechanical parts that need a bit of flex without snapping.
PETG sticks to print beds extremely well—sometimes too well. If you print PETG directly onto a smooth glass bed or smooth PEI sheet without a release agent (like gluestick or hairspray), it can permanently fuse to the surface and tear chunks out of your bed when you remove the part.
Beginner Material Specifications
| Material | Tensile Strength (MPa) | Modulus (MPa) | Elongation (%) | Max Temp (°F) |
|---|---|---|---|---|
| PLA | 57 | 2900 | 8 | 130 |
| PETG | 46 | 1675 | 25 | 176 |
Intermediate Filament: Functional & Flexible
Ready to level up? These materials require a printer that is properly dialed in, and you’ll start needing specific hardware like enclosures or direct-drive extruders.
ABS & ASA
ABS is the traditional heavyweight of functional prototyping, but ASA has largely stolen the spotlight in recent years. ASA offers similar mechanical properties and high temperature resistance, but adds incredible UV resistance, making it perfect for outdoor use. Both are fantastic for parts that will see real-world wear and tear.
Never try to print large ABS or ASA parts on an open-frame printer in a drafty room. The material shrinks rapidly as it cools, leading to severe warping and layer splitting. Furthermore, they emit styrene fumes when melting, which have a noticeable odor and are a respiratory irritant. Always print in a ventilated area with a proper enclosure.
Nylon (PA)
Nylon is a semi-flexible powerhouse. It is incredibly tough, abrasion-resistant, and has high temperature resistance. It is the go-to material for printing custom gears, living hinges, or drone chassis parts that need to survive high-speed crashes. However, it is highly hygroscopic (it absorbs moisture from the air rapidly) and must be actively dried before and during printing.
TPU (Thermoplastic Polyurethane)
TPU is your go-to flexible filament. It’s used for everything from custom phone cases to drone bumpers and shoe insoles. TPU hardness is measured on the Shore A scale—85A is very squishy, while 95A feels more like a hard skateboard wheel. Because it's like trying to push a wet noodle through a tube, TPU typically requires a well-tuned direct-drive extruder to print without jamming.
Intermediate Material Specifications
| Material | Tensile Strength (MPa) | Modulus (MPa) | Elongation (%) | Max Temp (°F) |
|---|---|---|---|---|
| ABS/ASA | 44 | 1940 | 10.5 | 221 |
| Nylon (PA) | 45 | 2100 | 8 | 221 |
| TPU | 8 | 70 | >350 | 175 |
Advanced & Composite Filaments: The Heavyweights
These materials represent the absolute ceiling of what prosumer and industrial plastics can do. They require serious hardware, high temperatures, and robust nozzles.
Carbon Fiber Blends (PA-CF, PC-CF, PEI-CF)
Over the last few years, chopped carbon fiber blends have taken the 3D printing world by storm. By infusing materials like Nylon (PA) or PC with tiny carbon fibers, manufacturers create filaments that are incredibly stiff, warp much less during printing, and offer a stunning, layer-hiding matte finish. PA-CF (Nylon Carbon Fiber) is now the gold standard for high-end robotic parts and strong automotive fixtures.
Carbon fiber, glass fiber, and glow-in-the-dark filaments are highly abrasive. If you print these with a standard brass nozzle, the fibers will literally sand the inside of the nozzle away, ruining it in a matter of hours. You must upgrade to a hardened steel, ruby, or tungsten carbide nozzle before printing composite materials.
Polycarbonate (PC)
Polycarbonate offers some of the best mechanical strength and thermal properties you can achieve without stepping into six-figure industrial machines. It's highly impact-resistant and incredibly rigid. The tradeoff? It requires extremely high hotend temperatures and a heated enclosure to prevent it from warping violently off the bed.
PEI, PEKK, and PEEK
Welcome to aerospace-grade manufacturing. These high-end polymers offer the absolute highest strength, impact and temperature resistance available in FDM 3D printing. PEI (often known by the brand name Ultem) is one of the few polymers certified for use on commercial aircraft. Printing these requires sustained nozzle temperatures well over 400°C and actively heated build chambers that would melt standard hobbyist 3D printers.
Advanced & Composite Material Specifications
| Material | Tensile Strength (MPa) | Modulus (MPa) | Elongation (%) | Max Temp (°F) |
|---|---|---|---|---|
| Nylon-CF | 85 | 5000 | 3 | 260 |
| Polycarbonate | 62 | 2400 | 8 | 250 |
| PEI (1010) | 56 | 2500 | 2.9 | 340 |
| PEEK | 101 | 3720 | 27 | 290 |
- PLA & High-Speed PLA are your best friends for high-detail, low-stress models that print incredibly fast.
- PETG is the easiest upgrade for parts that need to survive the outdoors or moderate heat.
- ASA and Nylon are fantastic for durable functional parts, but demand an enclosure, ventilation, and a dry-box.
- Carbon Fiber Blends (PA-CF) offer incredible stiffness and a beautiful matte finish, but require hardened nozzles.
- Don't confuse Strength (holding static weight) with Toughness (surviving an impact or bending).
Which filament is the easiest to print?
PLA (and modern High-Speed PLA) is widely considered the easiest filament to print. It doesn't require a heated bed (though one helps), it rarely warps, and it prints flawlessly on almost any machine right out of the box.
Can I print ABS or ASA without an enclosure?
While you might get away with very small parts, printing ABS or ASA without an enclosure generally leads to severe warping and layers splitting apart due to uneven cooling. An enclosure is highly recommended for success.
Why is my Nylon print making a "popping" noise?
Nylon absorbs moisture from the air incredibly fast. If your filament is popping, hissing, or producing stringy, brittle prints, it is "wet" and needs to be dried (see our guide) in a filament dehydrator before printing.
Why did my carbon fiber filament ruin my nozzle?
Standard brass nozzles are too soft for composite filaments. The chopped carbon or glass fibers act like liquid sandpaper, widening the nozzle hole and ruining your extrusion in a matter of hours. Always use a hardened steel, tungsten carbide or ruby nozzle for composites.
3 comments
Can you update your filament guide to include ASA?
Thanks
Hi Sherman,
If you go to any of our filament product pages you will find exactly what you are referring to. We give a complete list of starting parameters you can use for each filament type.
Thank you,
how about making a page or a chart that has an average ( Filament) tip-temp bed- temp and whatever else you can fit in like run speed, nozzle size and so on It would be a great help for newbies trying to learn !!
TKS for listening SHERM