Carbon Fibre PETG prints at about 250 °C with a 80 °C bed and 30% part cooling. Usable range 240–265 °C nozzle, 70–90 °C bed. Abrasive — needs a hardened nozzle.
PETG-CFCF PETG
Starting settings
Nozzle
240–265 °C (start 250)
Bed
70–90 °C (start 80)
Part fan
20–50% (start 30%)
Wall speed
20–40 mm/s
Max volumetric flow
8 mm³/s
Shrinkage
0.35%
Softens at
80 °C
Enclosure
Helps
Nozzle size
0.4 mm or larger — 0.6 mm recommended
Nozzle material
Hardened steel required — this is abrasive
Drying
65 °C for 6 h
Speed
Slower again than plain PETG, 20–40 mm/s. Fibre-filled material rewards patience and punishes flow spikes.
Bed surface
Textured PEI. Glue stick as a release agent on smooth sheets, same as plain PETG.
Nozzle
Hardened steel, 0.6 mm strongly preferred — fibre plus PETG's stickiness is a clog combination.
What bites people
Hardened steel nozzle required, and 0.6 mm clogs far less than 0.4 mm.
Strings noticeably LESS than plain PETG — the fibres reduce the stringy behaviour. A pleasant surprise if you have fought plain PETG.
Stiffer and more dimensionally stable, but more brittle. Good for jigs and brackets, poor for anything that flexes.
Still hygroscopic. Wet PETG-CF prints rough and weak just like the plain version.
Safety
Nozzle above 240 °C.
Abrasive — hardened nozzle required. Do not sand without a mask.