Carbon fiber PET: stiff, strong & stays flat on large parts.
Best for
Parts that must not bend, sag or move: long arms carrying weight, heavily loaded gears and pulleys, precision jigs, load-bearing outdoor parts, and large parts that must stay flat.
What people make with it
- Wall hooks and arms carrying heavy things (a bike, tools)
- Heavily loaded gears and large pulleys
- Precision jigs and fixtures
- Load-bearing outdoor parts
- Large flat panels and long parts that must stay straight
Specs
- Softens at
- About 75 °C / 167 °F
- Stiffness
- Very high (carbon fiber filled)
- Large parts
- Stays flat: our first choice when a large part would warp
- Surface
- Matte, hides layer lines
Typical values for this plastic, rounded. How strong a part is also depends on its shape and the strength you choose.
Good to know
- More brittle than PETG: it snaps instead of bending, so it's wrong for clips, snap-fits and hinges
- Only at Strong or Heavy strength
- Costs more than PETG
PET-CF or something else?
- PETGPETG is tougher (bends before it breaks) and comes in more colors; PET-CF is far stiffer and won't sag.
- PET-GFPET-GF is a little less stiff but tougher, the better pick if the part takes knocks.
- Nylon CF (PA6-CF)Nylon CF handles much more heat; PET-CF is steadier in humid air and costs less.
Design tips
- Use it where you can name the reason: stiffness, a steady load, outdoor load, or a large part staying flat.
- Give clips and thin flexing features a different plastic: PET-CF snaps rather than bends.
- Matte finish hides layer lines, good for visible functional parts.
Not the right choice for
- Clips, snap-fits and living hinges (choose PETG)
- Parts that get dropped or struck (choose PETG or PET-GF)
- Small chunky parts: they're already rigid, so PETG Strong is tougher and costs less
Colors (3)
- Black
- FDE Earth
- Olive Drab Green
Screen colors are a guide; the real plastic can look slightly different.
Strength options
Plastic parts aren’t solid inside. You choose how much plastic goes into each part:
- StrongExtra walls & fill, for parts under load
- HeavyStrongest; dense enough to sink
PET-CF is only offered at the strengths above.
Which one? Economy for models and fit checks, Balanced for everyday parts, Strong for parts under load (brackets, mounts, gears), Heavy for small solid parts that take big loads and for anything that lives underwater. More strength costs more: it uses more plastic and printer time.