Lets talk TESTED filaments

Like probably everyone here I have heard all the anecdotal information about different filaments and how one is better at so and so than the other. What really interests me is people actually testing filaments and not just going by marketing hype.

Three youtube channels that I like for this are CNC Kitchen, Zack Freedman, and especially My Tech Fun. There are others of course.

The general feel I get from this is that PLA is the strongest, ABS/ASA is the best at heat resistance, and TPU is the flex king. Everything else is just slight variations on a theme.

What I mean is that when actually put to the test, PETG is no stronger than PLA, and might be a couple of degrees more temperature resistant but not enough to make a difference and carbon fiber filaments are actually weaker than PLA (see Clough42’s tests).

In my own personal use tests I have noticed that the “same” material from different manufacturers can be wildly different and even different colors of the same material from the same manufacturer can be different. This has caused me to do things like print a production part I needed black in gray filament, then sand and paint it black. Wild, but it works and solves a problem.

So I have pretty much settled on four basic filaments for the majority of my printing; PLA/PLA Pro+ from Hatchbox for some production and all of my test prints (almost all test prints are done in Hatchbox blue PLA), Polymaker Polymax PLA for any production pieces that don’t need serious temperature/UV resistance, Polymaker ASA for anything that needs temperature/UV resistance, and Polymaker TPU for the flexy bits.

In the past six years or so, these are the filaments I have found to be worth using and provide consistently good products. What are yours and why?

As you may know, the plastic parts in a Prusa MK3 printer were themselves 3D printed, and all of those parts, except maybe a couple holding the hotend, are printed from PETG. Why PETG? I don’t know, but I doubt it was an arbitrary decision. I’m fairly sure, though, that PETG is something greater than “a couple of degrees more temperature resistant” than PLA and maybe even the deciding factor in favoring it over PLA.

So, what do I print the most? PETG. It doesn’t stink while printing like ABS, and it doesn’t melt/droop at lower temperatures like PLA. And it’s fairly cheap, even if not the cheapest.

That said, I’m getting very interested in trying PET-CF and, if I can ever figure out how to print it, PEEK. The downside is that they require annealing to get the full benefits. However, PEEK is almost as strong as some metals, or so I’ve read. The payoff? At least in theory, It’s a lot easier to print a part than it is to mill it out of a block of aluminum.

Filaments vary so widely between manufacturers that it’s hard to make generalisiatons. Further, manufacturers sometimes change their formulas - they can’t even make 2 rolls the same color sometimes.

Also people have different use cases - for example you’re mentioning strength but not elasticiity or weather resistance.

Here in Singapore PLA won’t last outdoors for very long and you pretty much have to use PETG or ASA for outdoor equipment.

As I mentioned in another thread there’s also different kinds of strength. PETG for example is usually more elastic than PLA and often bends more easily, even though it mah be harder to break. I had a spring catch printed in PETG fail for this reason, where PLA is known to work. (Had to change the design of the part to get around that).

edited for spellings.

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Fair enough, but without generalizing it will be hard to answer your question. :wink:

Which is one of the reasons there are so few actually useful “filament testing” resources and websites! :slight_smile:

For me PLA is a useless plastic, it’s far too hot where I am to use it for anything useful. (11am and it’s 40°C ambient, yesterday it hit 51°C :sweat: if want ot dry filament I just open the bag and leave it on the table :smile: ) An example, you print some parts for your Ender and every week you need to tighten all the bolts again. PLA creeps too much when under any load regardless of the temperature. Prusa use PETG as it has better load characteristics or long term stability. I use bambu and other brands of ABS because it has much better properties and with the X1 in my workshop it’s easier to print than PLA. I printed the Bambu mouse in PLA and ABS, and the ABS one looked much better because ABS doesn’t lift up on the corners and then hit the nozzle.

And then there’s something that nobody mentions about ABS. Due the way it shrinks it’s much easier to design for, if need parts to fit together I don’t use any clearance. So I can print a part with a 10mm hole and another with a 10mm pin, and they will fit together snuggly. My theory is that outside diameters shrink smaller and hole shrink bigger, where as PLA you’ll need to add 0.1 at least to get them to fit.


I’ve often wondered why a filament made by manufacturer #1 might print without issue, but a roll of filament of the same type and color made by manufacturer #2 might be total ■■■■. Remember those small rolls of sample filament that Creality used to ship with their printers? Those would be a good example of what I mean by total ■■■■. Also, I’m speaking about this example in the past tense as I don’t know whether or notfilament production at Creality is the same these days as it used to be. I only know that in the past, a lot of people commeneted upon as if it were true.

Likewise, even in the current day and age, it’s not uncommon for different manufacturers to recommend a different print temperature range for the same color filament of PETG or PLA. What’s up with that? It makes me wonder whether maybe some manufacturers are cutting costs by substituting some amount of cheap garbage feedstock (perhaps whatever is cheapest in the market on that day when they go out looking for cheap substitutes) into their main production. I don’t doubt that this would be possible to do as long as the substitution percentage is kept low enough. On the other hand, if they get too gready, then maybe that would explain why the delivered formulations can end up so seemingly different.

It’s funny, but I watched CNC kitchen for quite a while to learn about filament characteristics through his testing, which sadly Stefan doesn’t really do anymore. I still reference his older videos on occasion to refresh my knowledge though. Igor with My Tech Fun is my current go to Youtuber that does some pretty great testing.

There are so many variables for how filament is decided, but in a general sense what you are saying is accurate. One other thing I’d point out, which can greatly decide what filaments you will primary print with, is whether a printer is open or enclosed.

My open unenclosed printers ONLY print in PLA, PETG, and TPU. Pretty much anything else would be better off with an enclosed printer and/or need some kind of fume mitigation. In these instances I print with PLA for testing/prototyping and for functional parts that need stiffness and won’t go outside. Fun story about testing with PLA … I made a cup holder for my wife’s Subaru out of PLA to test fitment with plans to later print in ABS. It’s been in her car for 2 years faithfully holding her coffee and other drinks without issue. When I only had open air printers, my go to filament for anything that would see the outside world, I’d print with PETG. There’s a reason that many people and companies prefer PETG for production parts; you can print it out in the open and not worry about dealing with enclosures or fume mitigation. My Lulzbot Sidekick is mostly printed out of PETG and it’s been doing great over the past few years.

With my enclosed printers, I no longer have a use for PETG. I primarily print in PLA and ASA. I still use PLA for testing/prototyping and for functional parts that live inside. For all other production parts, I print it out of ASA. I skip ABS since ASA is functionally the same, but includes UV resistance for just a bit more cost. For me the next level of part making has me moving to PC and Nylon. PC for its great strength and stiffness which would replace ASA for parts that need extra heat resistance and stiffness. And then nylon for parts that need wear resistance like for making gears.

So those are my filament types I generally print with or plan to print with in the near future. Any other filament is just not worth the time, money, or effort unless it was for a super specific property I need for a part. The carbon fiber filaments are all just noise to me; they are pretty and all, but mostly either weaken the base material or give stiffness to a material that really isn’t worth it since there’s others that are just as good or better at that aspect for a cheaper cost.

Now for what brands I use. I used to just buy cheap filament from Micro Center, which honestly has done okay, but isn’t always consistent. I still will sometimes buy it when its on sale to try out weird types and colors. Now I mostly use Hatchbox since it’s sold by a store up the street from my job and Polymaker after trying out a couple of free roles of PLA and ASA I received. Those two filaments have done very well for me with their consistency and quality. I’ve really wanted to try out Bambu’s filament since I’m a big fan of the idea of using refills, but with with their stock issues I have no plans to use them. So for now I’m almost exclusively using Polymaker filaments.

I hope @Olias chimes in on this thread. I know he’s been working on testing out filament brands that can be purchased through Amazon to find the most reliable at the cheapest cost.

Are you saying that you’re able to vent directly to the outside atmosphere from inside your print chamber? That would certainly be ideal.

My connection isn’t yet that good. Instead, for a near-term project I’m working on, I’ve positioned my X1C inside a small bathroom. However, as with all bathrooms, that bathroom has a vent directly to the outside. I can control the bathroom vent motor via an Amazon Basics wi-fi on/off switch. So… I turn on the vent fan prior to starting a print, and I let it continue to run until I think the room has likely been fully evacuated of any pollutants. In theory I have some VOC and particle detector sensors which would tell me when the coast is clear, but it turns out that the sensors I have don’t seem to be sensitive enough to provide adequate guidance in that regard. If I were printing something stinky like ABS or ASA, then maybe the sensors I have would would be a better match for detecting that kind of severe pollution.

Yes that’s correct, I have a my X1C vented to the outside world. I also run a bento box inside the chamber and an air purifier in the room. It’s honestly a bit overkill, but it’s in my home office and I spend a lot of time in there while its printing.

My vent setup consists of the following:

  • A window insert made out of plywood with insulation laminated between. Where it butts up to the window frame, I have weather stripping to create a seal. I cut a hole in it to fit a louvered dryer vent.
  • On the inside I have a 4 inch flexible duct going from the dryer vent to a 65 cfm duct fan that’s configured to blow air outside.
  • From the fan I have a 4 inch flexible duct hose reduced down to a 3 inch flexible duct hose. The 3 inch hose is attached to a self designed 2 part hose attachment that’s connect to the chamber fan exit on the back of the printer.
  • The 2 part rear vent adapter has the body attached to the back plate of the printer over the chamber fan. It utilizes 1 available screw and the 3 blank holes around the fan that I’ve tapped to fit m3 screws. The 2nd part fits on the end of the 3 inch duct hose. Both the base and the hose adapter connect to each other via magnets to make removal easy for maintenance.

The X1C, bento box, duct fan, and air purifier are all connect into my Home Assistant server so that I can manually control and setup automations for various features. Example: anytime the printer chamber fan turns on, my duct fan automatically turns on with it.

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If you think PEEK is easier to print than an aluminium part is to machine you’re in a for a big, big shock.

Because they’re not the same material, PLA and PETG, etc, are generally the bulk of a filament but not all of it, there are various mixes and alloys to increase wettability, help with crystalisation, even the core PLA compositions themselves can be different in terms of chain lengths and viscosities, thermal conductivity makes a difference to melt rates, etc. You can do things when drawing the filament to increase the surface hardness with a soft core so it drives better, etc.
Pigments are different between manufacturers, and even in manufacturers different pigments/colours have different effects on the properties, and some colours need far more additives than others, etc. Good manufacturers try to balance those properties across the whole colour range, some just throw out whatever works out the cheapest.

One manufacturers PLA is not the same as anothers, just because they’re called the same.


You may well be right: I got some online “instant quotes” on what it would cost to have somebody else print a part in PEEK for me, and it was thousands of dollars for even a humdrum part without much detail to it.

So, I changed my goal to PET-CF, which the X1C should be able to handle.

You’re talking 140-200c bed and chamber temps, 380-400c nozzle temps and you still need to make the part geometry warped from what you want initially - to compensate for it warping as it cools. Easy and PEEK are not words that go together. You use PEEK when you have to and nowhere else.

Good 'ol Material Science. I really wish that those materials and processes used were more transparent, but I know that’s the secret sauce for these filament vendors.

strength and temperature resistance are only two of many characteristics that play a role when selecting a filament.
For me, one of the most important has become creep. That is, if a part is under enduring bending load, all printing materials start to change their shape permanently even if the load is removed. This a widely ignored and underrated property in my opinion. I have tested myself PLA (Bambu basic), PETG (Bambu basic) , ASA (redline ASA X) and PC (Polymaker Polymax PC) in fairly controlled test.
PLA was terrible, ASA mediocre, PETG mediocre and PC excellent. I was quite surprised about PETG, because that was my goto alternative if PLA failed a task due to creep.
For heat resistant filament, ABS is just the beginning at ~90°C i deflection temp. PC resists up to 110°C. For higher resistance, different variations of Nylon go up to 180°C deflection temperature (e.g. Polymaker PA6-CF). That is only materials that can be printed in an X1C or P1S.
For outdoor use, nothing compares to ASA because it is UV resistant like no other material that can be printed on consumer printers.
Then there is stiffness. Depending on the use case you either want some flex in your parts or they should be very rigid. Most rigid filaments are typically different base materials with embedded carbon fibers, e.g. PET-CF, PETG-CF, some PAx-CF. From the four filaments i mentioned above, the stiffest was PC, closely followed by PLA, ASA has some softness and PETG a bit more.
Another property is abrasion resistance. E.g. if the printed part rubs over a rough surface how easily it is grinded. If that is relevant, then you want Nylon.

Most of that isn’t my own experience but what is common knowledge. Only the creep and stiffness test was done by myself.