Transparent PETG Basic - Any tips?

Anyone in the community printed this yet? Does it need any post processing to be truly transparent? Thanks in advance. I have a spool I’m about to do a test print on.


I have created a print profile that you can experiment with on Maker World. I’d be happy to receive any feedback, as I’m aiming to gather a wealth of information from various sources, along with my own adjustments, in an attempt to create an ideal profile. While it’s still a work in progress, it’s in a very promising trial phase that I take pride in. I call it:

How to Print Ice! :ice_cube:

Printing transparent PETG to be as clear as possible requires very slow speeds and a set of special settings. I believe I have enough information on the page that should get you started.


There was an interesting article on YouTube that Stefan over at CNC Kitchen posted. It got me truly interested in trying this out with Transparent PETG. Truth be told. I never got anywhere near his results on my P1P. I even tried Polycarbonate and transparent PLA and I wasn’t even close to what was in this video. All I could get was a frosted glass look.

I am eager to try out ExtremeElementz profile and see if that does the trick.

I have a very specific project where I’m trying test the feasibility of creating a Fresnel lens which should lend itself to FDM printing if I can get the filament to come out clear. So far, no luck.


Thanks @Olias, I value your feedback as one of the go to people in this community. If you do end up trying it out I’d greatly appreciate any feedback you had.

The profile has been created and adjusted via settings from all over the maker space. I’ve seen the videos and read the blog posts in hopes to refine it. Using my “How To Print Ice” PETG profile you should get a really clear sample.

I haven’t started entertaining bridges or threaded parts as you truly need some cooling so it’s still quite a work in progress but I was happy enough with the profile I decided to released it as v1.00 (Currently on v1.01).

I will try it here in a few minutes and let you know how it goes

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Thanks for putting this together (and the humor :laughing: )! I’m out of transparent PETG but I have transparent PCTG (which is supposed to be better) as well as transparent PC-PETG. I’ll adapt your filament settings and see how this comes out! (Can one print ice on a 100C bed in a 40C chamber??? :stuck_out_tongue_winking_eye:)

So far the experiments I’ve done after seeing CNC Kitchen’s video have been meh. BTW, you may want to try out (and publish) a 0.6mm nozzle based profile, IIRC Stefan’s experience is that the bigger nozzle produces clearer ice (fewer layer lines). It also produces stronger vases…


I appreciate your feedback, I do plan on going with bigger nozzles in the future due to that very reason you mentioned. I know it’s nothing special, just a profile that people can load up and test but I wanted it to be unique so I added some comedic reading at points.

I have more of plans for the profile in hopes people will want to stop by and check it out or give reasons to see progress but it’s in the beginning stages for sure. A single Ice Sample takes about 1 hour to form so testing values has taken a good amount of time. But people who don’t care to about creating profiles and all that can still come to the page and print out a nice Ice sculpture and still get something awesome.

For the record I hate Bambu’s formatting system for Bambu Handy lol I have spent more time than I’d like to admit in tweaking and adjusting fonts and settings. Lol it’s terrible!

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First result with HZST3D PC-PETG filament ($25/kg):

That looks pretty good when placed right on top of the background. You can see how the thicker face of the “cube” has a pretty dirty color. Not great IMHO.

A problem I see is that the top layer is printed with the boosted flow and that causes a ribbed top surface, which detracts from the transparency:

I believe that it would be good to set “top layer flow ratio” to 0.9x to back out the boosted flow. E.g., if the flow is boosted 5% from optimum (which is what I did for my sample) then it should be 0.95.

When the background is a bit away from the cube one can’t really see through all that well anymore (the ribbing is a bit part of the problem):

Overall pretty darn good first try! Thanks for the profile!

Q: do you really find that 18mm/s speed is noticeably better than something like 50mm/s?


@3dsurfr Thank you for trying it out! I haven’t tested that filament but I have heard it can be better than PETG. It’s interesting to see how different transparent filament responds to the profile. I do see the yellowing that is inherent in a lot of transparent filaments in your test print. Here was my last test with v1.00 to show how clear it can be.

I do think I’d like to look at the top layer flow ratio as I have not experimented with that setting before, but overall I think a .6 or .8 nozzle will really make this profile come alive even more.

Here is the Ice Sample at 7mm above the text.

I do think the layer lines depending how you view the Ice Sample can alter the view/transparency.
Now to answer your question about speed, although I haven’t tested your filament, with PETG yes at higher speeds the print starts to become cloudy.

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Your print profile worked great. These pictures don’t do justice.

Zero post processing. It just worked. Thanks so much! Uploading from my phone. Hopefully I did this correctly. Printed on X1C with Engineer plate. Going to give the P1P, P1S and mini a go next.


They sure turned out great! Thank you. I’m glad the profile worked for you; I really think the Ice Rose looks so good. It’s a great starting point for the profile and enables people to try out different things. I wouldn’t say it’s fully optimized for objects, but with some extra tweaking, I’ve managed to print a popular filament clip, and that center area, when zoomed in, totally looks like ice. Overall, it’s not super clear due to adding a bit of cooling, but it’s fun to experiment with the profile.

I appreciate you testing it out, definitely share the photos in the comments section if you can. :ice_cube::cold_face:

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Wait, isn’t this the comments section? Oh, duh, on MakerWorld👍🏻

I picked up the Best-Q PCTG print this morning: it’s definitely way better than the PC-PETG one:

Not glass-clear when placed 2cm in front of the background:

PCTG on the left, PC-PETG on the right:

For the PCTG print I set “top layer flow rate” to 0.95, having boosted the flow ratio in the filament profile by ~5%. It looks like I could tune that a bit more, perhaps also try ironing. I printed at 20mm/s instead of 18mm/s. Next I’ll try 50mm/s…


Wow. Holy cow is that a stunning improvement just with the PCTG filament change. I have to get me some of that filament. One day we shall print the clearest of ice! :crazy_face:

Yup! It’s $29/kg on Amazon in the US, so a pretty good deal. It prints cleanly and is a bit stiffer than most PETG.

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So I had great success with this profile. It also reminded me why I switched to Orca. I’ll post that in another thread but this has been the first time using Bambu Studio since I switched to Orca fulltime. I did this because I wanted to gain the experience of downloading from Makerworld using the slicer while also preserving the integrity of print profile as ExtremeElementz had intended without introducing another variable in the experiment.

Mind you, my ultimate goal is to reach optical transparency not translucence. Any filament can do translucence but I wanted to get resin-like clarity or close to it.

You be the judge. I used the models mentioned in CNC Kitchen’s video.

Here are the results.

From right to left:

  1. Original Ice-cube model included in ExtremeElementz Makerworld profile.
  2. A cut block model from CNC kitchen cut to 5mm this using the same setting as the one on the right.
  3. The exact same block but one very light coating of triple thick polyurethane paint. (BTW) the same affect can be achieved by just wetting the surface of the untreated block.
  4. Left most is the original block from CNC kitchen and I feel I got similar results as Stefan.

Side by side using the 5mm thick cut block(unlaminated) and the original model. Printed on the same plate however, the model were printed in by object sequence as opposed to layer mode. More about that in a moment.

Top-down view

Here is a closeup of top-down where you can really see the optical clarity. Note, These are 5mm thick and you’re looking downward through almost 15mm of media.

The top down view shows that looking through a large segment of the media, you can get very clear optical clarity. In fact, I looked at it under a 40X jeweler’s loupe then looked at a kitchen glass that has been through countless cycles through our dishwasher and the kitchen drinking glass was no more optically clear than the PETG that was coated with a single coat of polyurethane.

Here is the glaze I used. Now some might say it’s cheating but in my view, I could have sanded this and polished it but there are so many models where sandpaper won’t reach but aerosol will so I elected to use this method in my post processing experiment.

This is the filament I used. I purchased this earlier in the year specifically to test out CNC’s kitchens findings. I was never able to produce the clarity he did until I used ExtremeElementz profile. :clap:

There were two tips I will share with folks.

  1. Set wall layers to 0. I noticed in the profile, it had first and top layers set to zero and that is what gave me the idea. It helps with optical clarity at the edge but only along straight lines.
  2. Print sequence using “by object mode” as opposed to “by layer mode” which is the default. Object mode prints each model one at a time. I found that when I tried to print in the default layer mode, the simple act of the head moving between models had a huge impact. It appears to allow the filament to get cold and interferes with the next layer. I found that if I could keep the nozzle moving over a single object for the duration of the print, this had a dramatic impact on optical clarity.

The “print by object” trick doesn’t bode well for larger objects, like an intricate vase, since there each layer is going to take time…

I like the polyurethane glaze idea. Didn’t know about this “triple thick” one. Now ordered…

I tried the “cube” at 50mm/s and the top layer is not as smooth. With the polyurethane it may not matter. But I still have some tweaking to do to get a smoother top layer. I don’t have any photos of my sample 'cause some of it got ruined by a contamination from another filament.

If you’re printing just one object, printing in object mode won’t make a difference. This is because there’s only one object on the plate. My experience was that when I ran multiple objects, the head travel to perform the next layer on the second or third object, was enough to cause the filament to cool and shrink sufficiently to create an tiny air gap. It’s that air gap that cause the cloudy translucent look.

Here’s an example of the first experiment I ran with CNC’s kitchen’s object. I was experimenting here with different ironing methods. As you can see, I never did achieve optical clarity at all. Sample #4 was at fill ironing and although it was the smoothest. the underlying filament still got milky. Then when I ran these one at a time using Sequence By Object, Viola!!! optical clarity.

BTW: The disk above it was a Fresnel lens. This is my holy grail and the whole objective behind me trying to achieve optical clarity. You can see by the sample that it was an unmitigated disaster. I’m still working on it though.

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Yes, I understand that :wink:. In your test you got poor results when it took N seconds between layers due to having multiple objects. By switching to by-object printing you cut that to N/5 (or something like that). But that means that if one prints an object with a large perimeter, like an intricate vase, or a large surface area like a sheet, then it may just take N seconds no matter what. So these things won’t be as optically clear. That’s what I meant by “it doesn’t bode well for larger objects”.

NB: it may also mean that for large objects there may be a trade-off with printing speed: doubling the speed may reduce clarity per-se but that may be compensated by a shorter per-layer time…

I Agree. Larger objects may not be possible to eliminate the cloudiness.

However, I did notice something in the Gcode that I want to experiment with. In some of my test prints, I observed that there was better clarity in the center of the circle prints compared to cloudiness at the edges. Upon further observation, I realized that the head movement was faster in the center, where it was making shorter strokes. I found the code “G1 F1140” at the beginning of every object line segment in the GCode. Although I’m not a GCode expert, I looked it up and found that the ‘F’ parameter represents the volumetric flow for that line segment. While it might be unreasonable to expect the slicer algorithm to adjust the volumetric flow for each line individually, for shapes like circles where we know the travel at the outer radius will be travel longer due to the longer distance and therefore have more opportunity to cool down, there might be a formula that could use a value like π to compensate for the speed/ volumetric flow or temperature difference at the outer diameter.

At any rate, I realize I am overthinking this but it sure would be great to figure this out.