ABS-GF

ABS-GF is familiar ABS reinforced with chopped glass fiber (typically 10–20%). The glass filling makes the filament noticeably stiffer and dramatically improves dimensional stability: the fibers hold back shrinkage, so parts warp less and keep their geometry better than plain ABS. It prints with the same demands — an enclosure and a hardened nozzle are a must — but in return gives you engineering-grade rigidity without jumping to pricier materials like PA-GF.

What it's good for

• Stiff engineering parts and brackets that must not flex under load
• Jigs, fixtures and tooling where dimensional accuracy and repeatability matter
• Housings and panels that hold shape under moderate heat (near electronics, in an engine bay)
• A drop-in upgrade for plain ABS where parts used to warp or drift out of tolerance
• Functional components that need stiffness and heat resistance but without the brittleness of carbon-filled ABS-CF

Where not to use it

• Impact or sharp-bend parts: glass fiber lowers elongation at break, making the material less ductile and more prone to chipping than plain ABS
• Thin flexible snap-fits and spring elements — the filler makes them brittle
• Decorative or visible glossy surfaces: the matte, fiber-tightened layers look technical, not pretty
• Printing on an open-frame printer without an enclosure, or on a brass nozzle — neither gives a stable result

How to print

• Nozzle temperature: 250–270 °C (start mid-range and tune by quality)
• Bed temperature: 90–110 °C
• Enclosure required: a closed chamber at 45–55 °C holds heat and sharply reduces warping
• Part cooling minimal or off — like plain ABS, active cooling weakens layer bonding
• Moderate speed, 30–80 mm/s; the abrasive fiber doesn't like high speeds
• Hardened nozzle (steel or wear-resistant coated), all-metal hotend, 0.4 mm diameter or larger
• Adhesion: ABS slurry or a brim, a flat heated bed; a brim helps on large parts
• Moderate retraction (1–5 mm): excessive retraction with a filled material raises the clog risk

Drying and storage

ABS itself is only mildly hygroscopic, but the glass fiber slightly increases its appetite for moisture. You don't need heavy drying like PA-GF, but after long storage it's worth drying the filament before printing. Signs of moisture: crackling and a 'popcorn' sound at the nozzle, bubbles and fuzz on the surface, and weakened layers.

• Drying: 60–70 °C for 4–6 hours
• Storage: a sealed box or bag with silica gel, away from humid air
• Moisture signs while printing: crackling at the nozzle, steam, bubbles, a fuzzy surface and weak layer adhesion

Pros and cons

• Noticeably stiffer than plain ABS
• High dimensional stability and less shrinkage — the part barely warps
• Keeps the heat resistance of ABS, convenient near electronics and heat
• Less brittle on impact than carbon-filled ABS-CF, at comparable stiffness
• A neat matte surface that hides minor print defects

• Abrasive — a hardened nozzle is mandatory, otherwise rapid wear
• Requires an enclosure and an all-metal hotend
• Lower elongation at break: less ductile than plain ABS
• Same ABS hassles when printing — odor and warping without a warm chamber
• More expensive than plain ABS and harder to dial in