I am trying to print some accessories for photography (gobos, scanning etc). To achieve the effects i need, the filament should be as non translucent as possible. As far as i understand, all filament is born more or less clear, and color is added with pigments.
So i assume that the best results would be happening with black filament? Is there a difference in translucendy (is that a word?) between materials? Like PLA vs ASA vs PETG vs some carbonfiber material?
Tia
Frank
If you stay away from āTransparentā Black you should be fine.
Any dark color should work fine.
I believe the word youāre looking for is āopacityā. There is no such standard among filaments but it should be very easy to determine by a 5 minute layer test.
Create a 100x100x1mm cube primitive for each sample you want to test. Then shine a bright flashlight behind it. This will immediately shine through less opaque filaments. Some materials such as black PC are quite translucent. While black PETG, less so. In my experience, the most opaque filament is anything with Carbon Fiber(CF) or Glass Fiber(GF). Those filaments are really find fibers of opaque material mixed in with the base filament that they are created for.
One property of CF filaments is that they are not only opaque, but they have a near zero specularity which makes them well suited to non-reflective surfaces such as a light hood or shroud. Add to that the fact that they accept flat black spray paint very well and you have a near perfect black, non-reflective body which has uses in photography.
If you could describe your specific use-case in more detail, it would help to refine the answer.
Just adding some info to @Olias detailed answer: thickness will significantly affect the light transmittance of a 3D printed surface (e.g. MW-TD_example). Additionally, adequate layer orientation can dramatically improve opacity.
With that in mind, for any filament, you can test (e.g. MW-TD-test) and define optimum printing settings for maximum opacity.
Edit: regarding colours, besides absorbing (black colour), you can eliminate transmittance by reflecting, i.e. the light stops at the surface. The best solution depends on your specific goal.
When I am making a sign that goes into a window, especially a double sided sign, I add a mod at the last bottom layer before the infill starts (or lowest top layer). The mod is one layer thick, and doesnāt go to the edge, but stops 1 or 2mm before. I then use black plastic for the mod. So you only see the color the sign is intended to be, and light doesnāt shine through because of the black layer so you donāt see the art from the opposite side of the sign.
Thanks for all the advise. To give a bit more detail, I am trying to print gobos for an optical spot. Those things are roughly 6.5 cm in diameter, and 0.5 to 0.7mm thick.
I tried it with black PETG, that in terms of opacity works well, but this material is then a tad to flexible. Ordered some black ASA, and will try that. If that is not working, yes, i was thinking about using CF or GF filament, but i have no experience printing with that.
Tx
Frank
Try test printing with PLA, so you donāt waste any filament.
PLA is stiffer then PETG & should show better results, ASA can be tricky.
And donāt rely on the same filament to behave the sameā¦ I received half a roll of bambu green filament with my printer with which I printed some tags with lettering cut-out (2 layers of green, 2 of black for the letters cut-out to show, rest in green). The green was very opaque and didnāt let the black through. When I ran out of bambu green, I purchased a fresh roll and when I printed the exact same tags, I wondered why it let the black be seen through. I fiddled with a lot of settings to understand until I realized (I had may be still 1m of my original roll so I re-printed one tag with it) that the new roll was a lot more translucent than the original and not by a small amount. I dried my new filament thinking it was it but to no avail, the composition of the new roll must have been very different. I tried a new roll since then and it is still very translucent.
Thanks for sharing that experience. And that, if nothing else, should shine a bright light on the fact that Bambu Filament is substandard when compared to other filaments in the same price category. I am still on my quest for the āreliableā $10 spool. My personal best is $13-$14 for PLA, and of the vendors Iāve used, they all outperform Bambu for similar filament.
Whatās interesting is how Prusa handles their filaments. They actually trace the manufacturing process back to the spool itself, where one can see the specs for that individual spool using the QR code on the box. To me, thatās kind of overthinking it, but you have to admire the fact that they bring the topic of quality to a whole other level with that amount of transparency and traceability in their manufacturing process. Also, their filament prices are in line with Bambu, despite what must be a world of difference in quality. I just wish they would expand their operation into North America.
Iāve said it before, but it bears repeating: if one is not using AMS where the spool matters, there really is no logical reason to buy Bambu over other manufacturers available on Amazon if you have Amazon Prime. For the US, that means either 1-2 shipments, and if you donāt like the product, send it back within 30 days for a full refund. I send back about 10% of my new spools, and Iāve been compiling a naughty and nice list. Some of the folks on the naughty list might be a surprise, such as Sunlu, whose quality on PETG was abysmal.
I donāt have an AMS (yet) but I only purchase bambu green and orange because I like the color of these bambu filaments otherwise I mostly use sunlu or whatever. I just purchased a CC3D PC blend filament as per your advise for instance :), still need to try it though.
Iād be interested in hearing your experience. That filament has become my filament of choice for constructing machinable parts. It isnāt the prettiest of filament, just average, but outside of ABS, I havenāt found anything that matches up to strength and durability in sunlight.
Just printed a Bambu cube with no filament calibration or anything. Iāve just used Bambu PC preset on engineering plate and result is very promising. Need to perform some hardness test and machining now 
Edit: Iāve just printed a very fine piece and noticed that 100Ā°C was really hot for the plate (I removed it before plate was cool enough and deformation ensued), may be due to the high PETG content of the filament. I will try some settings in between PC and PETG and run calibration tower to select right hotend temp. What do you use as presets for the CC3D PC?
