3D Printing Info

Filament comparison

PETG-CF vs TPU soft

Compare printing settings, strength, heat resistance, dated prices and sources.

Carbon-fibre PETG (PETG-CF) guideSoft TPU (below 85A) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PETG-CF comparisonsMore TPU soft comparisons
PETG-CF vs TPU soft — documented properties and sources
PropertyCarbon-fibre PETG (PETG-CF)PETGSoft TPU (below 85A)FLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$29.99/kg median; $16.00–$74.22/kg across 11 dated product listings$114.04/kg median; $109.80–$122.27/kg across 4 dated product listings
Identity & Market
Base polymer / chemistryPETG reinforced with chopped carbon fibre[1][2]Very soft thermoplastic elastomers below 85 Shore A. Fiberlogy's FiberFlex 30D measures 81 Shore A, the softest grade with a published datasheet found here[3]
Densityg/cm³1.25 (Bambu Lab) to 1.34 (3DXTech), ISO 1183; Prusament 1.27[1][4][2]1.07 (Fiberlogy FiberFlex 30D, ISO 1183)[3]
Typical priceUSD/kg1 kg-equivalent spools span 16–74; the middle of the market is about 29[1][5][6][7][8][9][10][11]1 kg-equivalent spools cluster near 115[12][13][14]
Price range across brandsUSD/kg16–74 across brands; ELEGOO 16 in a 5 kg pack, Reli3D 17, SUNLU 20, IEMAI 22, Siraya Tech 25, Bambu Lab 32, Sakata 3D 53, 3DXTech 67, Prusament 70, Filament PM 74 on 0.5 kg spools[15][1][16][5][6][7][8][9][10][11]110–122 at 1 kg-equivalent; Recreus 70A 110 and 60A 116 at 500 g, NinjaTek Edge 83A 112, NinjaTek Chinchilla 75A 122; the Recreus 3 kg spools fall to 70–73[12][14][13]
Market availability1–5Stocked by most mainstream brands[1][16][5][15]Niche, a handful of specialist brands[3][17][12]
Spool sizes & diameters1.75 and 2.85 mm; 0.75 and 1 kg spools[16][1]1.75, 2.85 and 3 mm; 0.5, 0.85, 1, 2 and 3 kg spools[3][12][18][13]
Typical applicationsStiff functional parts and fixtures where PETG's toughness is traded for rigidity and a matte finish[1][2]Highly compliant seals, soft grips and prosthetic liners[3]
Diameter tolerance± mm±0.02 (Prusament)[2]Not documented
Printing Parameters
Nozzle temperature°C240–270 (Bambu Lab); 265 ± 10 (Prusament)[1][2]Not documented
Bed temperature°C65–75 (Bambu Lab); 90 ± 10 (Prusament)[1][2]50–70 (Fiberlogy FiberFlex 30D)[3]
Enclosure / chamber requirement1–5Open frame fine; draught shield helps — Bambu Lab specifies a 35–50 °C chamber[1]Open frame is fine[3]
Recommended chamber temperature°C35–50 (Bambu Lab)[1]Not documented
Part cooling fan0–60 % (Bambu Lab); 50 % (Prusament)[1][2]Not documented
Bed surface & adhesion aidTextured PEI or engineering plate with glue (Bambu Lab)[1]PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[19][20]
Maximum volumetric flow (mm³/s; see test conditions)mm³/s11.5 on My Tech Fun's Bambu Lab PETG-CF profile[21]Not documented
Bed-adhesion difficulty1–5Needs the right surface or a thin adhesive[1]Not documented
Stringing / oozing tendency1–5Slight — the fibre reduces stringing against unfilled PETG[1][22]Not documented
Overall printing difficulty1–5Intermediate — dry filament and a tuned profile; hardened nozzle mandatory[1]Expert / industrial hardware only — below 85 Shore A the filament buckles in almost any feed path that is not a short, constrained direct drive[18][20]
Extruder requirementNot documentedDirect drive only, with a constrained filament path; Bowden is not viable at this hardness[18][17]
Hardware Wear & Reliability
Nozzle hardness required1–4Hardened steel required[1]Brass fine indefinitely[23]
Abrasiveness1–5Highly abrasive — standard CF composite[1]Non-abrasive[23]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle; 3DXTech specifies a hardened 0.4 mm minimum nozzle and 0.25 mm layers or higher, and Prusa lists composites as a higher clogging risk[24][25]High — jams from moisture, heat creep or particles; below 85 Shore A the filament buckles and compresses, and Simplify3D warns that raised feed rates most likely end in a jam[19][20][26]
Heat-creep / jam sensitivity1–5Slightly sensitive[22]Very high — softens in the cold zone readily[20]
Hotend requirementHardened steel nozzle; no high-temperature hot-end needed[1][22]No special hot-end required, but a direct-drive extruder is (Simplify3D)[19]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Low — 0.30 % saturated at 25 °C / 55 % RH (Bambu Lab)[1]Moderate[26]
Equilibrium moisture content at ~50 % RH%0.30 saturated at 25 °C / 55 % RH (Bambu Lab); Prusa measures 0.10 after 7 days at 22 % RH[1][2]Not documented
Drying temperature & time65 °C for 8 h (Bambu Lab)[1]Not documented
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface[26]Bubbling and popping at the nozzle, stringing and a rough surface[26]
Effect of moisture on strengthNo dry-versus-conditioned figures published; Bambu Lab states PETG-CF must be properly dried before printing and stored dry after use[1][26]Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[26]
Storage requirementSealed with desiccant; Bambu Lab says store dry after use[1][26]Sealed with desiccant; often kept in a dryer during the print[26]
Mechanical Properties
Tensile strength (XY)MPa35 ± 5 (Bambu Lab) and 47 ± 2 at yield (Prusament) printed XY, ISO 527; 56 at break for 3DXTech[1][2][4]Not documented
Young's modulusMPa2460 ± 230 (Bambu Lab) and 1700 (Prusament) printed XY, ISO 527[1][2]Not documented
Elongation at break%4.3 at yield (Prusament, printed XY, ISO 527); 3 at break for 3DXTech[2][4]870 at break (Fiberlogy FiberFlex 30D, ISO 527) — the highest elongation in the dataset[3]
Flexural strengthMPa68 ± 3 printed horizontal, ISO 178 (Prusament)[2]Not documented
Flexural modulusMPa2300 printed horizontal, 3100 printed vertical, ISO 178 (Prusament)[2]Not documented
Other impact dataCharpy unnotched 29 ± 6 printed horizontal and 43 ± 8 printed vertical (Prusament, ISO 179-1); Izod 4.91 kJ/m² on My Tech Fun bars[2][21]Not documented
Layer adhesion / Z tensileMPa29 ± 4 printed Z (Bambu Lab, ISO 527); 18 ± 3 by Prusa's interlayer adhesion test; 10.7 on My Tech Fun bars[1][2][21]Not documented
Brittleness1–5Brittle — snaps with little warning[4]Very ductile — bends far before failing[3]
Hardness (scale-specific)Shore A / Shore D / Rockwell77 Shore D (Prusa Polymers method)[2]81 Shore A and 30 Shore D (Fiberlogy FiberFlex 30D, ISO 7619)[3]
Creep resistance / sustained load1–5Below average — a 12 mm bar sagged to 16.4 mm over 5 days at 1.25 kg, less than plain PETG's 19.4[21]Poor — no creep test at this hardness; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[27]
Fatigue / repeated-flex resistance1–5Moderate — no CF-grade S-N curve; unfilled printed PETG ran 79 000–193 000 cycles at 30 % of tensile strength[28]Excellent — living hinges viable[20]
Elasticity / flexibility1–5Rigid[1]Rubbery / highly elastic[3]
Z strength as % of XY%83 (Bambu Lab, printed Z against XY tensile)[1]Not documented
Wear resistance & frictionNot documentedTear strength 95 kN/m (Fiberlogy FiberFlex 30D, ISO 34-1)[3]
Thermal Properties
HDT at 0.45 MPa°C74 (Bambu Lab) and 96 (Prusament), ISO 75 at 0.45 MPa[1][2]Not documented
HDT at 1.8 MPa°C68 (Bambu Lab) and 80 (Prusament), ISO 75 at 1.8 MPa[1][2]Not documented
Glass transition (Tg)°C68 (Bambu Lab) and 80 (3DXTech), DSC[1][4]Not documented
Melting point / Vicat°C225 melting (Bambu Lab, DSC) — the carbon fibre lets the PET fraction crystallise[1]170 melting (Fiberlogy FiberFlex 30D, DSC)[3]
Continuous service temperature°C77 — loaded bars begin to move at this temperature, against 61 for Bambu Lab PETG Basic[21]Not documented
Flammability / UL 94Flammable; no UL 94 rating published[1]Not documented
Environment & Chemical
UV resistance1–5Moderate — a season or two; the carbon fibre does not add UV stabilisation[29]Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[20]
Chemical resistanceWithstands acids, alkalis, oils and UV exposure, as for unfilled PETG[29]Withstands industrial solvents and UV exposure (Polymaker)[20]
Food contactNot certified for food contact[29]Not food safe without specific certification (Polymaker)[20]
Biodegradability / compostabilityNot biodegradable[29]Not biodegradable[20]
RecyclabilityFibre-filled PETG is not accepted in household plastic collection[29]Not accepted in household plastic collection[20]
Electrical & ESD propertiesSurface resistance above 10⁹ ohm/sq — carbon fibre at this loading is not static-dissipative (3DXTech)[4]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[30]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[30]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[30]Open a window / occasional ventilation[30]
Dust & fibre handling hazardCarbon fibre is bound in the matrix; sanding dust should not be inhaled[4]Not documented
Post-Processing
Sanding & machiningSands to a matte finish more readily than unfilled PETG[22]Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[20]
Gluing & solvent weldingCyanoacrylate; no common solvent welds it[22]Cyanoacrylate bonds TPU; no common solvent welds it[20]
Vapour / chemical smoothingNo practical vapour smoothing[22]No practical vapour smoothing[20]
Support material pairingSupport for PLA or its own material (Bambu Lab)[1]Polymaker warns TPU supports are often very difficult to remove[20]
Dimensional accuracy & detailMatte finish hides layer lines; stringing is reduced against unfilled PETG[1]Not documented
Solvents & Solubility
Soluble inNo common workshop solvent; dichloromethane — a carcinogen — dissolves the matrix surface, 1,2-dichloroethane destroys it in a week.[31][32]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[33]
Softened or crazed byAcetone (+16 % weight over 1 year at 23 °C), ethyl acetate, toluene and DMF swell and soften it; methanol crazes it.[31]Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[33]
Solvent welding & smoothing agentDichloromethane reaches only the resin, so the fibre is left standing proud of the surface. Controlled carcinogen.[32]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[33]

Material entries describe families or representative grades, not an interchangeable specification for every spool. Test methods, orientations and conditions may differ. Unknown values are marked “Not documented”. Prices and source dates remain historical snapshots; check the linked guide for product details. Differences highlight text, not a universal winner.

Sources for this comparison

  1. Bambu Filament Technical Data Sheet — PETG-CF Bambu Lab · 2026-08 · tds
  2. Prusament PETG Carbon Fiber Technical Datasheet Prusa Polymers · 2026-08 · tds
  3. FiberFlex 30D Technical Data Sheet Fiberlogy · 2026-08 · tds
  4. CarbonX Carbon Fiber PETG Technical Data Sheet 3DXTech · 2026-08 · tds
  5. Printed Solid product catalogue Printed Solid · 2026-08 · vendor
  6. SUNLU PETG-CF (PETG Carbon Fiber) 3D Printer Filament 1 kg SUNLU · 2026-08 · vendor
  7. Fibreheart PETG-CF Pro Filament product page Siraya Tech · 2026-08 · vendor
  8. IEMAI CF-PETG 3D Printing Filament product page IEMAI 3D · 2026-08 · vendor
  9. Reli3D Carbon Fiber PETG Filament 1.75 mm, 1 kg Reli3D (Amazon US) · 2026-08 · vendor
  10. PET-G CF15 Sakata 3D Filaments · 2026-08 · vendor
  11. Filament PM CFJet technical data sheet (TDS CFJet ENG.pdf) Filament PM (Plasty Mladec) · 2026-08 · tds
  12. Recreus product catalogue Recreus · 2026-08 · vendor
  13. Chinchilla product page — print guidelines, spool sizes and price NinjaTek · 2026-08 · vendor
  14. NinjaFlex Edge product page — durometer, print guidelines and price NinjaTek · 2026-08 · vendor
  15. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  16. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  17. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  18. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  19. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  20. TPU — material basics Polymaker Wiki · 2026-08 · doc
  21. BambuLab PETG Basic vs Translucent vs PETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  22. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  23. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  24. CARBONX PETG+CF — product page (print recommendations) 3DXTech · 2026-08 · doc
  25. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  26. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  27. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  28. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  29. PETG — material basics Polymaker Wiki · 2026-08 · doc
  30. Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments (Azimi et al.) Environmental Science & Technology 50(3) 1260-1268 · 2016-01 · paper
  31. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  32. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  33. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds