PETG–HF.
SAME STRENGTH.
3× FASTER.
PETG-HF is Bambu Lab's answer to one of FDM printing's most persistent complaints: PETG prints slowly compared to PLA. "HF" stands for High Flow, and the filament is reformulated at the polymer level to melt and flow through a nozzle two to three times faster than standard PETG while retaining virtually all of PETG's mechanical properties.
If you like PETG's tough, water-resistant, chemical-resistant, moderate-heat-tolerant profile but have been frustrated by its slower print speeds, PETG-HF is the same material without that trade-off. For most functional parts we print at Spool Foundry, PETG-HF is now our go-to over standard PETG.
What it is
Standard PETG has a relatively high melt viscosity. When a printer pushes hot PETG through a 0.4 mm nozzle at 20 mm³/sec, the molten polymer resists flow — requiring slower print speeds or larger nozzles. Bambu Lab reformulated PETG with different glycol ratios and modifiers to reduce melt viscosity, allowing faster volumetric flow rates without overheating the polymer or sacrificing layer bond strength.
The practical result: a well-tuned Bambu Lab printer can push PETG-HF at 32 – 40 mm³/sec of volumetric flow, compared to 12 – 18 mm³/sec for standard PETG. On a large part this translates to 30 – 50 % total print-time reduction with no measurable loss in tensile strength, impact resistance, or temperature rating.
Technical properties
- EXTRUDER TEMP
- 240 – 265 °C (higher than standard PETG)
- BED TEMP
- 70 – 80 °C
- ENCLOSURE
- Optional
- MAX FLOW RATE
- ~ 32 – 40 mm³/sec (2 – 3× std PETG)
- GLASS TRANSITION
- ~ 80 °C (same as std PETG)
- HEAT DEFLECTION
- ~ 70 °C
- TENSILE STRENGTH
- ~ 48 MPa (~5% below std PETG — negligible)
- IMPACT RESIST.
- Medium-high (equivalent to std PETG)
- ELONGATION
- ~ 4 – 100 %
- WATER ABSORB.
- Low — still hygroscopic once opened
- LAYER ADHESION
- Excellent (arguably better than std PETG)
- COST
- Slightly higher than std PETG
Pros
- Massive print-time reduction. Large functional parts that would take 18 hours in standard PETG can finish in 10 – 12 hours with PETG-HF. For customers on tight deadlines this is a meaningful difference.
- Same mechanical properties as standard PETG. Strength, toughness, temperature tolerance, and chemical resistance are statistically identical. You are not giving up durability for speed.
- Better layer adhesion in many cases. The lower melt viscosity promotes better inter-layer fusion, which means the weak axis (perpendicular to layers) is actually stronger than with standard PETG in our testing.
- Less stringing at speed. Standard PETG strings badly at high speed; PETG-HF is designed for it and strings less, meaning cleaner prints with fewer post-processing surprises.
- Good surface finish at speed. Because the material flows more freely, you don't get the "ringing" and under-extrusion artifacts that haunt standard PETG at high print speeds.
- Available in all the same colors as Bambu Lab's standard PETG lineup.
- Printable on any direct-drive FDM printer, not just Bambu Lab machines — though the full speed advantage requires a printer that can actually push the volumetric flow rate.
Cons
- Higher print temperature. PETG-HF wants 250 – 265 °C, hotter than standard PETG. Cheap hotends or PTFE-lined extruders may struggle or burn out faster at these temps. Our Bambu Lab machines have all-metal hotends rated well above this range.
- Slightly more expensive. Filament cost is 10 – 20 % higher per spool. If you're printing small parts on a slow machine the cost-vs-time math may favor standard PETG; on large parts at full speed the savings in print time usually dominate.
- Still hygroscopic. PETG-HF absorbs moisture like standard PETG and must be dried before printing long jobs.
- Marginally lower tensile strength. About 5 % below standard PETG in controlled tests. This is within normal batch-to-batch variation and is not noticeable in any real-world application we've encountered.
- Not a replacement for ABS or PAHT-CF. PETG-HF is still PETG — it does not survive above 80 °C, has the same UV sensitivity, and does not have the stiffness of carbon-reinforced materials.
When to pick PETG-HF
- Any functional part you would otherwise print in standard PETG where turnaround matters.
- Large enclosures, housings, or brackets where total print hours push into the double digits.
- Production runs of the same part where cumulative time savings multiply.
- Rush orders where every hour counts.
- Parts with tall, flat surfaces where standard PETG ringing or under-extrusion shows. PETG-HF handles high speeds more cleanly.
- Outdoor, garage, or workshop parts — same use cases as standard PETG.
- When you'd normally pick PETG but the customer is on a deadline.
When not to pick PETG-HF
- If your printer can't reach 250 °C stably — use standard PETG.
- Very small parts (< 30 min print time) where the flow-rate advantage doesn't compound.
- Ultra-budget jobs where the small filament price difference matters more than the hours saved.
- Anywhere standard PETG would already be wrong — hot environments above 80 °C, direct sunlight for years, rigid load-bearing applications. The formulation change does not fix PETG's fundamental limits.
Design tips for PETG-HF parts
- Design guidelines are identical to standard PETG. Wall thicknesses, infill percentages, thread design, fillet radii — all the same.
- For very large parts with thick walls, PETG-HF's flow rate is limiting only at the extruder, not in the design. You can design wider wall lines (0.6 – 0.8 mm) to further reduce print time.
- If you want to mix PETG-HF with standard PETG in a dual-material print (for cost or color reasons), they bond to each other perfectly since they're the same base polymer family.
Our take
PETG-HF is a rare case of "better in every way" from a material update. For most customer orders where we would historically print standard PETG, we now quote PETG-HF by default — it's faster, equivalently tough, cleaner-surfaced, and only marginally more expensive. The time savings alone often cover the filament price difference on medium-to-large jobs.
If you've ordered PETG from us before, PETG-HF is the natural upgrade. If you're ordering for the first time and your part sounds like a PETG job, we'll probably recommend PETG-HF on the quote.
Still not sure?
Describe your part and we'll tell you whether PETG, PETG-HF, or something else is the right call. Use the contact form — no charge, no obligation.