Is PETG-CF / PLA-CF better than plain PETG/PLA?

Use PLA-CF or PETG-CF when you want the fiber row and you already have a nozzle the store page accepts. The threads here do not prove it is stronger than plain PLA or PETG. Carbon fiber, AMS, drying, PETG, and PLA are the guides.

The rows

Bambu PLA-CF lists 190–230 °C (374–446 °F) and a bed of 50–70 °C (122–158 °F), with a hardened nozzle recorded. The US store page says a 0.2 mm nozzle is not compatible, a stainless nozzle is not recommended, the AMS series is compatible, and the diameter is 1.75 mm ± 0.03 mm. It also says to dry the filament before use. The page does not print the 190–230 °C (374–446 °F) nozzle. That range is the catalog row. Bambu PETG-CF lists 220–250 °C (428–482 °F) and 70–90 °C (158–194 °F), hardened nozzle recorded, drying hours blank. PolyLite PLA-CF lists 190–230 °C (374–446 °F) and 50–70 °C (122–158 °F) and links a data sheet. ELEGOO PLA is the plain comparison at 190–230 °C (374–446 °F) and 35–65 °C (95–149 °F). PLA and PETG hold both the plain and the CF rows.

What failed

r/3Dprinting 1wvf0h4 is Flashforge PETG-CF that looked, under a microscope, like metallic flecks rather than fibers. The score-91 comment says microfragments can still be fiber. The score-74 comment says it looks like sparkly PETG. The score-65 comment says the wrong PETG arrived. A score-3 comment says fiber stiffens the same plastic and makes a sharp load more likely to snap. Another score-3 comment says strength tests usually favor the unfilled filament. Those two comments are the strength talk in this set.

r/FixMyPrint 1gnujeo is PETG-CF that crackles on an A1 with AMS. The score-24 comment says moisture, and that some PETG takes almost two days to dry. The score-6 comment says sizzle, bubbles, and steam are wet filament. The score-10 comment says keep abrasive CF out of the AMS. The A1 page is the printer. Two days is the comment. The PETG-CF row does not list drying hours.

r/BambuLab 1c2ps4w asks if two PLA-CF parts differ because one is wet. The score-11 comment says a clog. The score-6 comment says a partial clog, from a recent PETG-CF print. A score-3 comment says PLA-CF sits wetter than other PLA and clogs if it cools in the nozzle overnight.

r/BambuLab 14t1d0o is Bambu PLA-CF stuck in a second AMS. The score-4 comment says the AMS did not pull the filament back from the toolhead. A score-3 comment says Bambu calls this filament AMS compatible and tells the poster to inspect the PTFE path.

r/functionalprint 13fi255 says PETG-CF printed a filter housing nicely. The score-6 comment is about refreshing carbon pellets, which is the filter media, not the filament. The P1S records stainless steel. The X1 Carbon records a hardened nozzle. The thread does not name which printer made the housing.

Questions