Carbon fibre filament doesn't make parts stronger the way most people imagine. The chopped fibres primarily add stiffness, dimensional stability, and creep resistance; tensile strength gains are modest. Knowing the difference is the whole game.
Where CF compounds earn their cost: parts that must not flex (brackets, mounts, jigs) and parts that must hold dimension across temperature swings. PETG-CF is our carbon-reinforced workhorse for exactly those reasons — stiff, stable, and on standard per-gram rates.
Where they're wasted: parts that fail by impact (the fibres make some materials more brittle), and anything where ordinary PETG was already stiff enough. We spec CF when the job needs it, not because it sounds premium.