3D Printing Info

Filament comparison

PEEK-CF vs PETG-GF

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

Fibre-reinforced PEEK guideGlass-fibre polyester (PETG-GF / PET-GF) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PEEK-CF comparisonsMore PETG-GF comparisons
PEEK-CF vs PETG-GF — documented properties and sources
PropertyFibre-reinforced PEEKHIGHTEMPGlass-fibre polyester (PETG-GF / PET-GF)PETG
Market snapshot
Listing priceUSD/kg; dated snapshots$597.50/kg median; $448.00–$695.00/kg across 5 dated product listings$27.38/kg median; $18.99–$29.99/kg across 3 dated product listings
Identity & Market
Base polymer / chemistryShort-fibre reinforced PEEK. 3DXTech's CarbonX grade is nominally 10 wt% carbon and its FibreX grade 20 wt% glass; LEHVOSS Luvocom 3F PEEK CF 9676 is 15 wt% carbon; Ensinger's machining stock runs to 30 wt% carbon[1][2][3][4]Glass-fibre reinforced polyester. Polymaker's Fiberon PET-GF15 uses a PET rather than a PETG matrix and carries 15 wt% glass fibre[5]
Densityg/cm³1.39 (ISO 1183)[1]1.43 (Fiberon PET-GF15, ISO 1183)[5]
Typical priceUSD/kg1 kg-equivalent spools span 448–972; the middle of the market is about 598[2][3][6]1 kg spools cluster near 25[7][8]
Price range across brandsUSD/kg448-972 across formats and filler types; IEMAI 3D CF-PEEK and GF-PEEK 448 at 1 kg, 3DXTech CarbonX PEEK+CF10 598 at 2 kg and FibreX PEEK+GF20 695 at 1 kg, Luvocom 3F PEEK CF 9676 648 at 2 kg[2][3][6][9]19–30 across brands; ELEGOO 19, Polymaker Fiberon 30[7][8]
Market availability1–5Niche, a handful of specialist brands[2][3]Niche, a handful of specialist brands[7][8]
Spool sizes & diameters1.75 and 2.85 mm; 200 g to 2 kg spools[2][3]1.75 mm; 0.5 and 1 kg spools[8]
Typical applicationsStiff aerospace and oil-and-gas parts where PEEK alone is not rigid enough[1]Stiff, dimensionally stable fixtures; the Fiberon grade is designed to be annealed for heat resistance[5]
Printing Parameters
Enclosure / chamber requirement1–5Actively heated chamber required[10][11]Not documented
Bed surface & adhesion aidNot documentedTextured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[12][13]
Warping tendency1–5Moderate — needs adhesion aid or draught shield; the fibre cuts PEEK's crystallisation shrinkage[1]Not documented
Bed-adhesion difficulty1–5Not documentedNeeds the right surface or a thin adhesive — the problem is releasing the part, not sticking it[12][13]
Stringing / oozing tendency1–5Not documentedModerate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[13]
Overall printing difficulty1–5Expert / industrial hardware only[10][11]Not documented
Hardware Wear & Reliability
Nozzle hardness required1–4Hardened steel required[1]Hardened steel required[5]
Abrasiveness1–5Highly abrasive — standard CF composite[1]Highly abrasive — standard GF composite[5]
Nozzle clog risk1–5High — jams from moisture, heat creep or particles; 3DXTech adds a hardened 0.4 mm minimum nozzle and 0.25 mm layers to the mandatory 120 °C pre-dry[14][15]Moderate — needs dry filament and a clean nozzle; Prusa lists higher risk of nozzle clogging for glass-filled composites[15]
Heat-creep / jam sensitivity1–5Not documentedSlightly sensitive[16]
Hotend requirementNot documentedNo special hot-end required[16]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Not documentedModerate (0.3–0.8 %) — the PETG matrix reaches 0.40 % saturated at 25 °C / 55 % RH; no glass-filled grade publishes its own figure[12]
Equilibrium moisture content at ~50 % RH%0.06 in 24 h on extruded CF30 stock (ASTM D570)[4]Not documented
Symptoms when wetNot documentedBubbling and popping at the nozzle, stringing and a rough surface[17]
Effect of moisture on strengthNo dry-versus-conditioned figures are published; 3DXTech mandates a 120 °C, 4 h pre-dry before every print because trapped water flashes to steam at these nozzle temperatures[14]Polymaker groups PETG with nylon, PVA and TPU as highly hygroscopic; no dry-versus-conditioned strength figures are published for this grade and the loss shows as bubbling and poor layer adhesion[17]
Storage requirementNot documentedSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[17][13]
Mechanical Properties
Tensile strength (XY)MPa105 at break (printed XY, ISO 527, CF10); 121 at yield on extruded CF30 stock (ASTM D638)[1][4]59.9 ± 0.8 printed XY, ISO 527 (Fiberon PET-GF15)[5]
Young's modulusMPa8100 (printed XY, ISO 527, CF10) — more than double unfilled PEEK; 6343 on extruded CF30 stock (ASTM D638)[1][4]4144 ± 133 printed XY, ISO 527 (Fiberon PET-GF15)[5]
Elongation at break%3 at break (printed XY, ISO 527), against 28 for unfilled PEEK[1][18]4.0 ± 0.5 printed XY, ISO 527 (Fiberon PET-GF15)[5]
Flexural strengthMPa136 (printed XY, ISO 178, CF10); 193 on extruded CF30 stock (ASTM D790)[1][4]104.2 ± 2.4 printed XY, ISO 178 (Fiberon PET-GF15)[5]
Flexural modulusMPa8300 (printed XY, ISO 178, CF10); 7171 on extruded CF30 stock (ASTM D790)[1][4]3705 ± 85 printed XY, ISO 178 (Fiberon PET-GF15)[5]
Charpy impact, notchedkJ/m²Not documented8.7 ± 0.6 printed XY, ISO 179, notched (Fiberon PET-GF15)[5]
Other impact dataIzod notched 61.9 J/m on extruded CF30 stock, converted from 1.16 ft-lb/in (ASTM D256)[4]Charpy unnotched 27.2 ± 2.0 printed XY (Fiberon PET-GF15, ISO 179)[5]
Layer adhesion / Z tensileMPaNot documented48.2 ± 0.3 printed Z, ISO 527 (Fiberon PET-GF15)[5]
Brittleness1–5Brittle — snaps with little warning; elongation falls from 28 % to 3 %[1][18]Brittle — snaps with little warning; elongation 4.0 % in XY and 2.6 % in Z[5]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M107 on extruded PEEK-CF30 stock (ASTM D785), against M100 unfilled[4][19]Not documented
Creep resistance / sustained load1–5Excellent — holds load for years. Ensinger rates carbon-fibre PEEK stock as very highly creep resistant and specifies 260 °C continuous service[4]Below average — no GF-grade creep test; the CF grades sagged to 14.8–16.7 mm over 5 days at 1.25 kg against 17.1–20.4 mm unfilled[20][21][22]
Fatigue / repeated-flex resistance1–5Good. Victrex rates PEEK for long-term fatigue as well as creep; the fibre cuts elongation at break from 28 % to 3 %, which limits repeated large-strain flexing[23][1][18]Below average — no GF-grade S-N curve; elongation at break falls to 4.0 % in XY against 5.2–9.3 % unfilled[5][24]
Elasticity / flexibility1–5Rigid[1]Rigid[5]
Z strength as % of XY%Not documented80 (Fiberon PET-GF15, printed Z against XY tensile)[5]
Thermal Properties
HDT at 0.45 MPa°C265 (printed XY, ISO 75 at 0.45 MPa, CarbonX PEEK+CF10) against 140 for unfilled PEEK[1][18]81.6 as printed, 133.7 after annealing (ISO 75, 0.45 MPa)[5]
HDT at 1.8 MPa°C316 on extruded CF30 stock, converted from 600 °F at 264 psi (ASTM D648)[4]71.8 as printed, 87.3 after annealing (ISO 75, 1.8 MPa)[5]
Glass transition (Tg)°C143 (DSC, CarbonX PEEK+CF10) — the fibre does not move the glass transition[1]59.5 (DSC)[5]
Melting point / Vicat°C334 melting on extruded CF30 stock, converted from 633 °F[4]231.6 melting (DSC); Vicat 232.6 (ISO 306)[5]
Continuous service temperature°C260 long-term on extruded CF30 stock, converted from 500 °F; 300 short term[4]Not documented
Annealing responseNot documentedAnnealing lifts HDT at 0.45 MPa from 81.6 to 133.7 °C[5]
Thermal expansion (CTE)µm/m·K14.4 (extruded PEEK-CF30 stock, ASTM D696; source states 0.80e-5 in/in/°F) — about a third of unfilled PEEK[4][19]20 along the print bead and 63–74 in the build direction at 30 °C (30 wt% GF, large-format printed, TMA)[25]
Flammability / UL 94UL 94 V-0 on the base resin; Ensinger lists extruded PEEK-CF30 stock as inherently flame resistant[18][4]UL 94 HB at 1.5 mm (Fiberon PET-GF15)[5]
Environment & Chemical
Chemical resistanceNot documentedWithstands acids, alkalis, oils and UV exposure[13]
Food contactNot documentedNot certified for food contact as filament[13]
Biodegradability / compostabilityNot documentedNot biodegradable[13]
RecyclabilityNot documentedNot accepted in household plastic collection[13]
Electrical & ESD propertiesSurface resistance above 10⁹ ohm/sq — not static-dissipative (ASTM D257)[1]Surface resistivity above 10¹² ohm — insulating (Fiberon PET-GF15, ANSI/ESD S11.11)[5]
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised. None of these polymers was in the chamber study, and all are processed far above the temperatures it covered[26]Moderate — measurable VOCs and UFPs, ventilation advised[26]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[26]Open a window / occasional ventilation[26]
Dust & fibre handling hazardCarbon fibre is bound in the matrix; sanding dust should not be inhaled[1]Glass fibre is bound in the matrix; avoid inhaling sanding dust[5]
Post-Processing
Sanding & machiningNot documentedSands poorly — the material is tough and gums rather than powders[16]
Gluing & solvent weldingNot documentedCyanoacrylate; no common solvent welds PETG cleanly[16]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing[16]
Support material pairingNot documentedPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[16]
Solvents & Solubility
Soluble in95–98 wt% sulphuric acid dissolves the matrix at 40–70 °C and leaves the fibre. Nothing else touches PEEK.[27][28]No common workshop solvent; dichloromethane — a carcinogen — dissolves the matrix surface, 1,2-dichloroethane destroys it in a week.[29][30]
Softened or crazed byConcentrated nitric, hydrofluoric, hydrobromic and hydriodic acids attack it; DCM, DMSO and THF swell thin-walled sections.[31][28]Acetone (+16 % weight over 1 year at 23 °C), ethyl acetate, toluene and DMF swell and soften it; methanol crazes it.[29]
Solvent welding & smoothing agentNone — no solvent softens PEEK, so parts are joined thermally or mechanically, never chemically.[31][28]Dichloromethane reaches only the resin, so the fibre is left standing proud of the surface. Controlled carcinogen.[30]

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. CarbonX Carbon Fiber PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  2. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  3. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  4. TECAPEEK CF30 black (PEEK-CF30) — stock shape properties Ensinger · 2026-08 · tds
  5. Fiberon PET-GF15 Technical Data Sheet V1.0 Polymaker · 2026-08 · tds
  6. IEMAI 3D CF-PEEK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  7. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  8. Polymaker product catalogue Polymaker · 2026-08 · vendor
  9. IEMAI 3D GF-PEEK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  10. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  11. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  12. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  13. PETG — material basics Polymaker Wiki · 2026-08 · doc
  14. CARBONX PEEK+CF10 — product page (print recommendations) 3DXTech · 2026-08 · doc
  15. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  16. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  17. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  18. ThermaX PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  19. TECAPEEK natural (PEEK) — stock shape properties Ensinger · 2026-08 · tds
  20. Extrudr PETG vs PCTG vs XPETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  21. Prusament PETG-CF vs PETG V0 vs PETG — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  22. BambuLab PETG Basic vs Translucent vs PETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  23. PEEK polymers — product overview Victrex · 2026-08 · doc
  24. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  25. Effects of Fiber Orientation on the Coefficient of Thermal Expansion of Fiber-Filled Polymer Systems in Large Format Polymer Extrusion-Based Additive Manufacturing Materials 15(8):2764 · 2022-04 · paper
  26. 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
  27. The Effects of Sulfonated Poly(ether ether ketone) Ion Exchange Preparation Conditions on Membrane Properties Yee, Zhang & Ladewig, Membranes 3(3) 182–195 · 2013-07 · paper
  28. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  29. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  30. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  31. What solvents are not compatible with PEEK? — fluidics technical FAQ IDEX Health & Science · 2026-08 · doc