IEMAI PETG Carbon Fiber Filament 1.75mm, Matte Black PETG-CF, Heat-Resistant, High Strength & Rigidity 3D Printer Filament, 1kg Spool Designed for Complex Models and Functional Parts

This filament is awesome. Honestly, it prints better than regular PETG. Yes, PETG alone is slightly flexible, but the introduction of carbon fiber changes all of that. Prints are stiff and strong, but there is a tradeoff in that prints are more likely to shatter if dropped or hit. This filament is so stiff that caution should be used when processing prints, so that you aren't cut or stabbed by your print. If you heat up your nozzle and pull off the ooze that forms, you pretty much have a needle, once it cools.This filament likes lots of cooling. The more air hitting the part, the less "foamy" the resulting print looks. It took me a bit to realize that it was the cooling that was causing my prints to look the way they did at first, and not an issue with my print temperature. Parts printed with this filament have a matte finish that helps hide print layer lines. The CF completely removes the shine of normal PETG.Order a spool and try it out...you won't regret it. This brand is also the cheapest I've seen on Amazon...great value for what you get.

I've been buying the same brand of CF-PLA for a few years now. They were out of stock, and this (IEMAI Carbon Fiber PLA) was both cheaper and in stock. (EDIT: Eight spools deep. I'm not going back.)For context; I print exclusively functional parts, not figurines etc.Print quality is outstanding, dimensional accuracy seems very consistent. Very low to no stringing. It handles vase mode prints very well; 8mm dia x 30mm length test pins printed very quickly (~80mm/sec actual) with no flaws. It bridges extremely well with high airflow -- honestly I've never seen better bridges from my printer.Info on my setup;- Extruder is a custom dual-drivegear 3:1 non-bowden extruder, hardened steel nozzle, 0.5mm bore, 0.3mm retract at 40mm/sec, heated to 223c- Bed is glass, coated with a light mist of hairspray diluted to a thin layer with a coat of water from a spray bottle, heated to 57c- Layer heights are usually 0.2mm or 0.25mm, outliers at 0.15mm and 0.3mm- Print speed began around 60mm/sec~90mm/sec with ~1500mm/sec^2 acceleration, but recent improvements and tunings has it closer to 90~120mm/sec @ 3500mm/sec^2 with 0.2mm to 0.3mm layer height, with negligible notable change in quality.It carves well if required, it drills well (unless you get it hot, obviously - it softens at a lowish temperature compared to hotter filaments, due to the PLA blend) and as stated it retains flawless dimensional accuracy. Ironed top surfaces look fantastic, and parts have a very satisfyingly solid sound when impacted. Side surfaces are smooth but grippy, a bit rougher than my normal brand of CF-PLA.I'll update this bit as I order more rolls, but thusfar:I've ordered eight rolls to date. I made no adjustments between rolls, and prints remained flawless with the exception of;- The first print or two (~100g) from the first roll had occasional blockages which self-cleared within the same layer; I'm willing to attribute that to possible contamination on my end.- The first few meters of the fifth roll, which needed a 5% feed reduction for 'perfect' surface finish.- One nozzle jam, less than one meter of filament from the end of the sixth roll. Would've killed the print, but it was on the final, small area on the very top layer. Cleared with cold pull at 150c.- Roll seven (Batch No 20221017ZD) had (to date) four clog issues which caused failed prints. Two abrupt, complete blockages fixed by hot-pull with no cycling after print cancel. Two partial blockages, one fixed via hot-pull, other fixed via cold-pull. I'd be more upset if these weren't non-final prototyping parts.- Most pics are before resonance tuning, so their surface finish isn't flawless. I also had some frame stability issues causing irregular layer height, which have been solved.- The ironing finish is astonishing. I've added three shots of 1mm thick, 115mm long vanes from an airflow project, with an ironed top surface. Ironing was 0.125mm, 20% flow rate, 30mm/sec. Lines are (BARELY) visible at this setting and using a 0.5mm nozzle; for perfection I would suggest 0.1@25mm or so. I'm not aiming for visible perfection with this project, so this is not an example of attempting such.- Also, three additional pics of the underside of the same vanes - I literally forgot to enable supports for the underside of a dead flat, unsupported, 2mm deep, 115mm wide overhang. It's tiny so it's impossible to get better pics, but it printed, perfectly. 500mm/sec bridging acceleration, 60mm/sec bridge speed, 0.98 bridge flow rate. I've honestly never seen anything like it.- I printed the auto-rewind filament holder, including the clutch and springs, from CF-PLA. I'm shocked to say, it has good spring-like qualities due to the TPU additive in the base blend, and the CF-on-CF clutch seems to be surviving very well so far. My extruder gearset is also printed from CF-PLA, and doesn't wear like I had expected -- this one gearset has lasted at least 12kg of printing so far.Sum total; seven rolls (~7.5kg by filament tracker) printed on one hardened steel nozzle (so far). Five failed prints from the same roll. No filament-derived bed adhesion issues. No layer adhesion issues. No significant diameter variances or other visible/brittleness problems with the filament. Roll seven aka Batch 20221017ZD has given me the most problems. If my experience were based on this roll alone, it would be three stars. Thankfully, I do know better. This is still 'my brand'.

I've been used to my prints always looking "printed" and having that tacky 3d printed look. While I don't mind it for practical prints, it doesn't always hurt to have a print that looks good while holding up. I've printed roughly ~500 grams of the filament so far and it's honestly printed better than any other filament I've used so far, even my Prusament PLA. Bed adhesion was good, and I even had a bit of a rough time taking some of my larger prints off of the build plate when it was cold. The main reason I bought the filament originally was for the strength aspect. It definitely holds up well in this regard. I've printed some vacuum attachments, socket and ratchet organizers, and some small nut drivers. Each of them held up perfectly fine. Don't expect it to perform any miracles, however, it's been my go-to filament and I will be buying more when I run out.(I figured I should mention, I'm using a Prusa Mini+. The only "upgrade" I've done was the z-axis brace but that really doesn't affect much other than vertical banding.)

I wanted to dip my toes in using filled nylons for stronger more durable, heat resistant prints than can be achieved with PLA/PLA+ etc. As with all nylons, this needs dried, even straight out of the package, typically at 80-90C (176-194F), printing from a heated enclosure (i.e filament dryer) at as close to drying temp as you can is recommended. Once I let the material dry for a day at 90c, I respooled some while still hot and somewhat flexible (filament is brittle by nature) and was able to get good results and layer adhesion. I have had some warpage, but not as bad as other filaments, and I attribute that to my own learning curveAs for supports, I have had by best luck (Bambu X1C) setting the support distances at 2x layer height. Less than that and you can't hardly remove them as this stuff likes to stick to itself and is tough. The main complaint is that this comes on a .5 kg roll that while being same OD as a 1kg roll, is half the width, meaning that I have to either use the external feed or respool to a more standard width roll, which adds it's own issues between time, as well as risk of breakage, and precluding the use in AMS. Fix the spool and this stuff is top notch

This is my new go to filament (PETG-CF) for functional parts. I'm really impressed. After fighting PETG, PAHT-CF, and PETG-HF for entirely too long, this filament printed perfectly on my P1S using the generic PETG-CF settings. The dimensional accuracy is great along with the strength and it looks even better than PAHT-CF. Im going to stick with this filament for the foreseeable. I've already ordered 4 more rolls.