How to create transparent 3D prints!

How to create transparent 3D prints!

I wanted to make something clear, but the
problem is that typical 3D prints, even if you use clear filament, just come out milky
white tone instead of being properly clear. They diffract light too much, so while the
light still passes though, it gets bounced around inside the parts and scatters, which
creates that translucent, but not quite transparent look. But Colorfabb have had this article online
for a while where they are showing off incredibly, impressively clear prints. I’ve done a lot of printing and I think
I’m ready to show you how to reproduce these prints yourself. Okay, let’s see, Colorfabb were using their
HT filament for this, which is Eastman’s Tritan, so I believe it’s the same material
that Taulman used to make, just plainly called Tritan, too. But the key here is that it’s a copolyester,
so a material that is very closely related to the common PET and PETG materials. In general, those are plastics that like to
fuse together extremely well, so they turn into one solid piece of material instead of
keeping those layer marks when you look through the print. I do have the Colorfabb HT filament here,
but I wanted to see how well just a standard PETG would do, so I did all my experiments
with the inexpensive DAS FILAMENT PETG, but I’m sure any other clear polyester filament
is going to work basically the same for this. I had two different use cases here, the first
one being these solid parts like Colorfabb showed that just look like they are one single,
solid block of plastic with basically invisible layer lines on the inside and outside, at
least that was the goal, the other one being vase-like structures that have no infill,
but only provide a shell, in my case, to scatter light. I was specifically looking into this for use
as diffusers for lamps of various types. And I think I pretty much achieved that. But let’s start with the solid parts. My test subject here is a spur gear from Daniel
Noree’s OpenRC F1 design, it’s got some relatively complex surfaces on the side, large
flat areas on the top and bottom and this hub that is a bit of a smaller element where
you’ll be able to see the light shine through from the top and the sides. I know, it’s not the most realistic design
for something that’s supposed to look good, but I think it’s a great object to tune
in the process. Plus, I’ve now clearly got plenty of spares
for when I start building my first OpenRC models! I’ll probably reprint these from ABS or
Taulman 910, though. So the first print was done with settings
that I thought would make sense – I used 300 and 350µ layers, 100% infill and regular
temperatures. But if you look at the part printed with those
settings, it is translucent, but it is not transparent. Yes, you can take a flashlight and shine it
through and the part will glow, but it’s not nearly as transparent as the samples Colorfabb
showed. So the first idea was to increase flow, to
close what looked like tiny gaps between the extrusion lines, so I upped the extrusion
rate to 105% first, and seeing that that improved things a bit I tried again at 110%. And if you compare the original part at 100%
flow and the new one at 110% it is already a lot more transparent, but we can also see
that it’s starting to show over extrusion streaking on the top surface. So at this point, the amount of material seems
like its correctly filling every gap, but the rest of the print settings could probably
still use some work. So I tried the other extreme, going with 50µ
layers, and that immediately helped a lot. I think because the hotend now passes over
the same spots more often and sorta irons down the tracks more, we’re fusing the individual
extrusion lines together more tightly to turn them into an actual, single block of material. In fact, if you look at this hub part that
I accidentally broke in half, you can see that both the surface where it broke and the
inside of the part look like one single piece of PETG, looking at just the crack, you’d
be hard-pressed to tell this thing was 3D printed at all. So next up, I tried increasing the material
flow on the 50µ prints and increasing the layer height from 50µ to 100µ, and both
improved transparency a bit. The 100µ print was done with more perimeters,
so you can see how those scatter light differently than solid criss-cross infill, but overall
it didn’t look like that different from the 50µ prints other than the top surface
being a bit less smooth and now looking more like it was overextruded.. The 50µ prints with more material I think
were the best ones of the entire series, where the one with a total of 15% extra material
looks, I think, extremely good, while the one with 20% extra is a bit too much and started
to get quite messy on the top and side. It also has these fuzzies between the gear
teeth where the nozzle was scraping off the extra material on each layer. For some reason, at the time I thought the
100µ prints were pretty much just as good as 50µ ones, so I kept on printing parts
with that setting. Looking back, I probably should have stuck
with 50µ. Anyways, these two benchies were printed with
110% flowrate, but this one got a bit of a temperature boost, hoping that would help
with everything fusing together. But instead, it turned out that the higher
temperature actually decreased the clarity of the part and had a few other negative effects
on quality. It’s a bit easier to see what exactly is
happening when you look at the gears that used different temperatures , and you can
see that, with a higher temperature, the PETG actually sorta starts cooking and bubbling,
and we’ll see that effect again in a second. In the main section of the gears, the higher
temperature is fine and slightly improves clarity, but up here at the hub, where the
printer slows down so that it doesn’t pump too much molten plastic onto one area in too
short of a timeframe, up here you can see the plastic getting extremely cloudy. That’s because when the printer slows down,
the filaments is sitting in the heated zone of the hotend longer and gets more time to
heat up, cook and degrade. So to avoid that, either disable the cooling
slowdown in the slicer or just print at a lower temperature overall. I think this Benchy does look really good
and shows off the transparency or translucency really well, but it’s most visible when
you look at the top and bottom of the parts, since it’s almost like the low layer height
makes the side surface somewhat milky. Maybe I should try with an even lower layer
height at some point, 10µ or something, but I’m pretty sure the Prusa i3 MK2 is not
up for that without dropping in a new extruder and some lower-pitch Z-axis spindles. The stock setup has a physical resolution
of 20µ, considering that the half-step position is the only microstepping angle you can really
trust. But let’s get back to these parts. I also tried to improve the surface by either
flame polishing it with a hot air gun set to 600°C or sanding it beforehand, but with
the hot air gun, this unsanded spinner started bubbling and softening up before it started
getting more transparent, so that part’s gone, and when I tried to sand a part beforehand,
yes, it did ultimately get a bit clearer, I think, after I heated the surface that was
sanded to 1200 grit, but again, it’s really hard to find that optimum spot where the plastic
neither bubbles nor softens up too much. But one nice thing you can do with heat, actually
for any filament, is to melt off the little hairs that PETG in particular likes to pull
when the hotend moves from one area to the next. High heat and a single pass are usually enough
to take care of them. And one last approach that didn’t really
work with the Benchy was the thicker layers at 300µ, even with the extrusion multiplier
cranked up, it did not turn out transparent at all. Though print quality overall was a bit more
consistent compared to the low-layer-height parts. So to recap for solid prints: With polyester
filament, use a low layer height, 100% infill, obviously, and tune the extrusion multiplier
so that you’re getting maybe a tiny bit of overextrusion. Higher temperatures can help, but it’s really
easy to cook your filament that way. Post-processing prints to improve the surface
is hard to do right, at least with heat. Maybe those thick coatings can help here,
I’ve played around with spray-on clearcoats before, but they didn’t improve things at
all. Awesome, let’s check out how these parts
were printed. These are all single-wall parts, most of these
you could print with vase mode, which is a print mode that turns the entire print into
one long extrusion line, instead of having discrete layers, it just continuously keeps
moving the hotend up as it lays down plastic, so it’s one long spiral. However, this shroud does have a ridge up
here, which usually can’t be printed cleanly with vase mode. But that’s not the point here. Let’s start out with what makes these parts
look better or worse than others, and essentially it’s the same thing again. It’s refraction wherever light transitions
from one medium into another, and here, that’s from the air into the plastic and back out. The layers act as tiny lenses because they
have that round section on their end. That’s why this part right here will blur
things in the vertical direction, but not as much horizontally. For example with this shroud, I tried to use
that effect and create tiny microlenses that would also diffuse light horizontally because
this is supposed to be a diffuser for a lamp. You know, you have these individual LEDs and
just seeing each one through a clear shroud doesn’t make for a very attractive lighting
setup, so I have all these parts that create different diffusion patterns. Most of these were printed with 300µ layers,
because if you compare it to the the one printed at 100µ, they are so much clearer and crisper
and less hazy white. Of course, using thick layers and only a thin
shell like this means that these parts print incredibly quickly and use very little material. This one was printed with just 25g of PETG
in 45 minutes, that’s hard to beat. This little one I printed with a thicker extrusion
width. But I can tell you one thing that doesn’t
work, and that is leaving the printer at over 600% speed for the wrong file, I mean, it
did get the print done super fast, but clearly, it’s not quite what I wanted. So typically, with a .4mm nozzle, you’re
going to set it up to lay down like 0.42mm wide tracks. Here, I went with a full mm, so two and a
half times as wide as the nozzle, and while it’s not the greatest thing to do if you
want overhangs and details to come out great, I mean, you should be using a thicker nozzle,
this part still came out looking great. It’s not quite as clear, instead it’s
very glossy if that’s the right word, but that might be due to the structure, too. It’s definitely better than using two individual
perimeters, which would introduce that second interface where you’d potentially end up
with more diffraction. Also, it’s very strong and stiff, as expected,
but I did crack the bottom when I tried to remove it from the PEI bed, PETG, as usual,
likes to stick to PEI a bit too much, so usually, I’d recommend using a liquid surface finish
on top of the PEI that doesn’t stick quite as much, so something like Printafix, or Magigoo,
or maybe Glue Stick if you can apply it evenly. But this technique of just using a single
wall isn’t great for every model. This Adalinda frog does come out really nice
looking with those thick layers, but wherever there’s a slope on the surface, the extrusion
lines just get super droopy, like on the back, near the tail or on the wings. I did configure this print with two solid
layers on top and bottom and turned off any features that backfill surfaces, which would
avoid these exact issues, but would also create these structures on the inside that just don’t
look great if you see the way they diffract light shining through it. Alternatively, you could print it with a solid
infill and thin layers, but that would use up a lot of material and take a long, long
time to print. So that’s how I printed these transparent
/ translucent parts. I think they turned out great, especially
these single-wall prints, they are going to look awesome installed somewhere with some
light in them. If you learned something, click that thumbs
up, get subscribed if you aren’t already and whether you’ve freshly subscribed or
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to ColorFabb’s HT material that will take you to the right shop for your region, also,
to the DAS FILAMENT PETG, that’s not an affiliate link, I just like the material,
it’s cheap, it consistently prints well, what more could you want. If you’re going to be shopping on Aliexpress,
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in the next one.

100 thoughts on “How to create transparent 3D prints!

  1. Isn't resin printing really, really good for clear prints? I know those machines are more for constant printing since the resin has a short shelf life compared to filament, and it needs more maintenance, but there's a lot of outsource companies that use dlp/sla. I'd say if you need a specialized print like that, that'd be the way to go.

    Also, what about that one thing, I forgot what it was called, but it was a vapor chamber for acetone or something? Supposedly that was supposed to provide clear prints with some filament.

  2. Tom have you ever tried the tribo filament from igus. It would be interesting to see how this filament compares to others when used as gears for open rc cars.

  3. why don't you use a acetonevaporbath for the 3dprinted parts? it makes even the ugliest prints smooth

  4. I would love to see the model for the diffuser you use @9:13. I think I can figure out the geometry, but it's tricky to see.

  5. Have you tried using acetone vapor as a post-print process to smooth out the surface and if yes, does it improve the optical properties?

  6. Hi Tom,

    I just discovered PEI film through this video and it seems very useful.

    I am having a hard time getting large PETG prints to stick to a print bed with blue masking tape due to warping, so this looks like a good alternative. If I understood correctly, I should use something like glue stick on top of the PEI to prevent it from getting stuck on the bed?

  7. I never have a problem removing items from the print bed. I cover the glass bed with painters tape. Once done I put the glass bed into a laundry tub with warm soapy water. After 15 minutes or less the print completely separates from the tape with 100 % success rate.

  8. Gaps of trapped air are the cause of the printed part's internal cloudiness. External causes can be dealt with post-printing.

    An interesting experiment would be to put a tiny 3D printer like a MP Select Mini or smaller inside a DIY, LED lit vacuum box with window and see what happens.

    Part cooling would need to be entirely radiative. Any fans might over-speed since with little or no air they would not be under any load. Probably a good idea to just disconnect them since they wouldn't serve any purpose anyway with no air. Stepper motor temps might also be a problem since there'd be no convective cooling. Possible fix – use low print speed? I've checked and electrolytic capacitors in the printer power supply and controller circuitry are OK under vacuum:

    "AIR PRESSURE – When operating at low values of external air pressure, there could also be an increase in the pressure inside the case. When an external vacuum exists, the pressure inside the capacitor could rise up to 1 bar. In these circumstances the internal vapour loss becomes greater resulting in an overall reduction in expected life."

    I suspect that the life reduction mentioned is only related to very long term operation.

    Anyway, such printing could turn out to be completely undoable (I'd guess the most likely fatal flaw would be the lack of printed part air cooling), but it might be an interesting experiment unless someone really up on 3D printer theory can explain why it's fundamentally not worth trying as I suspect it could easily be.

  9. @Thomas Sanladerer is that possible to print something as thin and as clear let say as a cd case kind of plane?

  10. #Thomas Sanladerer , have you tried using this method , getting a transperrent look

  11. Here's a thought… manufacturers just stop trying to sell something that comes out translucent as transparent. Just sell it for what it is instead of trying to force define it as what is not.
    Then… just being honest these days may be asking too much of anyone.
    Nice to see they at least have PETG now… something I asked several filament companies about over a year ago. even mentioned it on one of your vids i believe.
    Maybe I'll start printing again.

  12. Thomas,

    Can you paint on PETG and mask off the clear parts you want. I want to shine a LED in a part but not have the whole thing glow just certain parts. What are your thoughts. Thanks in advance.

  13. I think that if you were to bake to meld the internal layers well and then sanded well, you could probably make any settings work.

  14. If anyone wants optically clear, I'd think it'd still involve a multi-step process. Just 3D print as you'd normally do, but polish and chemically treat the part as needed for an extra smooth surface. Then make a silicon release mold of the 3D print. This would then allow you to do an a resin casting with something like an acrylic-epoxy, which should be as close to optically clear as you can get.

    So printing custom lens assemblies and the such are possible, but not as straight forward as putting a special filament in your 3D printer. (At least for now.) Also with "mirror in can" spray paint, custom reflectors may be possible by coating the backside of the clear casting.

    At least the idea is out there, I wonder if somebody has successfully tried it yet?

  15. The fogging or haze seen in that PETE filament is something that's noted by soda manufacturers. PETE naturally becomes hazy over time.
    Flame polishing seems like the best bet, but, rather than re-melting bits, you should aim to have it oxidize small layers off of the piece entirely without remelting the greater whole of the print.

  16. I may not have got it right, but aren't all those prints done with PETG? I waited for some colorfabb (supposedly created with transparency in mind) prints.

  17. Try to lightly heat part with propane torch. Maybe external layers will slightly melts without melt down all part 🙂

  18. I haven't done any 3D printing (yet, waiting on my first printer being delivered), but I've worked in injection moulding for 20+ years and have a little experience with PETG. To achieve a high degree of clarity you want to dry your filament for about 3-4 hours with warm air (at least 70c, PE, PET, PETG are hygroscopic) and with a desiccant material in the airflow. Once dried you can reduce the heat to 40-50c but it must remain in a dehumidified chamber if you're going to print for more than 1 hour as it will absorb moisture from the air (that's what causes the spitting and burning at high nozzle heats, you want high nozzle heats). You need to cool the print quickly to retain the semi-crystalline structure, the longer it takes to cool, the less crystallinity will be retained. Big fans and a lot of them! High speeds increase crystallinity too, as the polymer moves through the nozzle tip the molecular chains align, the faster it moves, the more they align (hence the higher extrusion rate improving clarity). Thin wall sections with 100% fill (in Injection moulding high pressure is always favoured for clarity). Small nozzle diameters will help with increased shear force on the polymer through increased exit speed, I would guess a .1 nozzle with .05 layer heights would be adequate, with print speeds as fast as your machine can handle.Maybe I'll make a video on print clarity one day, when I get comfortable with my printer, I'd prefer to see you beat me to it though!

  19. Can someone summarize this who had the patience to sit through the overly polished presentation of all the things that didn't work?

  20. Lol wtf why are you stabbing your gear with a chisel. Try putting the chisel on the edge and tapping it with a hammer or your fist like a chisel it supposed to be used…. can also sand down a paint scraper to get it really thin and that works well

  21. Very cool, but I would imagine that just air getting in the filament while and during printing and the layering, regardless how thin, will make even the most transparent filament cloudy or fogged.

  22. I have also find out, that retraction could make a bit different. With retraction enabled, it was much milkier than without retraction. At least for smaller parts.

  23. ฅ'ω'ฅ can you make vape glass tube with that clearly 3D printing?
    i really hate glass so badly they easy brake on me and i rather have plastic tube for my vape so wont brake too quick and they dont sell any glass tube or plastic tube anymore im stuck in middle nowhere and i find your youtube video be helpful i dont have 3D printer and i cant afford $300 i just wanted asked you if you could make plastic tube for koas erebus 30mm same is vcmt 30mm and i cant find size i been looking around for it

  24. for you solid part sanding then polishing would give best results thos objective being to remove the layer lines for the final layer

  25. an acetone wipe or spray could probably make the surface really smooth and is fairly easy, easier than sanding a smooth finish. i dont know if acetone works on petg but it does on other plastics.

  26. I would really like to know where to get that dark turqoise/cyan filament hanging on the lower row behind you in the video.

  27. Looks like the 3D printing is still pretty primitive and coarse at this stage. Not something easy for the consumer to do anything useful with

  28. Die Überschrift ist ziemlich irreführend. Hatte mir erhofft, dass es eine Anleitung für eine smarte Nachbearbeitung ist. Schade.

  29. a slightly domed nozzle helps a lot to massage the air pockets out of the hot plastic and get solid, glass clear prints out of PETG. ideally use a raft, or very high initial bed tem, to prevent the first layers from cooling too quickly. this still works with thicker layers but certainly not for all prints. clearcoat makes the finished product look much more transparent too.

  30. There must be some postprocessing techniques to make prints 90% more transparent, rather than these white semi-translucent prints. I have the feeling you should have done a bit more research and you shouldn't have used the term 'transparent' for prints which are clearly only a bit translucent.

  31. @Thomas Sanladerer: Thanks for sharing. Do you think it would be possible to replicate a Konica Minolta MPP-1000 screen protector (manufacturer's part number 6181910) designed for Konica Minolta Maxxum 7D camera? Minolta is no longer in business after selling it to Sony, and the latter just doesn't care about the existing Minolta camera owners. At all.

  32. Great video keep it up, I would really appreciate if you post a video on how to make the print stick to the bed for PET and PETG filament. I sometimes struggle in printing this material and sometimes it prints smooth and perfect, I am so confused about this and why sometimes it works and sometimes it doesn’t. Thanks for your help 🙂

  33. the other day i dipped a black ABS part, into acetone with clear abs dissolved in it, and the layer lines pretty much vanished entirely…….. so this might help with clear abs prints…… and maybe, if you can find something to dissolve PETG, you could use a similar method for it.

  34. Hello everyone, i am looking for a company to 3D print a clear object, just like Thomas did. Anyone can name a company ? I tried several hubs using 3Dhubs, but no one actually did print something clear… If you could name a company or advise a website, that would be great , guys ! thanks

  35. Sometimes the plastic needs to be dried first. Moisture can cause cloudiness. Perhaps taking the cloudy parts in an oven for a day or two say at 85 C then elevate the temperature to about 10 C below the glass transition temperature.

  36. The lampshades were wonderful. What term did you search for to find the LED lights inside? Or maybe a link please? What power do they use?

  37. Have tried to create a cover to keep the air warm around your printer? It may be that the temperature shock changes the surface, cooling too fast.

  38. What's the best way to diffuse LED string lights so that you don't see the hot spots of each individual LED? I've tried clear and white PLAs and PETGs with varying thicknesses, but the hot spots are still very visible.

  39. Basics of what I'm getting from this instruction video using PETG family of filament is to push the flow or extrusion value a bit over standard settings; use 100% infill, use lowest layer height extruder and printer will provide; use a higher temp but watch to not overcook and lose transparency; post processing can help.

    My experience with post processing has been disappointing in regards to improving transparency. Problem I believe is internal micro-bubbles created with laying down of the layers that surface smoothing is unable to touch. Another problem is the slicer’s print pattern. With Slic3r, the best I’ve been able to achieve is cross-hatch of 45 degrees which is also prominent in the videos examples. Cura allows this pattern to be adjusted to a single line angle with no cross-hatching. This gives better results but still leaves a discernable line. In any regards, there are examples (and stories) of folks gaining amazingly clear transparency but how this has been achieved escapes me? There also appears to be disagreement of line height that I’m observing from Google searches. Some are saying thick and even suggest exceeding nozzle diameter and others, as recommended here, smallest height possible. This also brings a question of line width but haven’t seen recommendations here. Should also note that virtually all say no cooling.

  40. I own a Prusa i3 MK3S. I bought a spool of transparent PETG from Sunlu. I've used many of their PETG filaments and I really like it. But for some reason, I've tried this transparent one and I am having trouble getting it to print. I've even used the same setting that I did with the black PETG and still it just doesn't print well at all. I've used the settings recommended on the sticker on the spool (200 – 220), still no luck. Not sure what to do.

  41. Did you ever post the light you were making? I still have a little bit of the filament I won from the competition you did with matterhackers a couple of years ago.

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