3D Printing Info

Filament comparison

PEEK vs PETG

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

PEEK guidePETG guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PEEK comparisonsMore PETG comparisons
PEEK vs PETG — documented properties and sources
PropertyPEEKHIGHTEMPPETGPETG
Market snapshot
Listing priceUSD/kg; dated snapshots$531.87/kg median; $296.14–$770.00/kg across 5 dated product listings$19.99/kg median; $8.99–$69.99/kg across 21 dated product listings
Identity & Market
Base polymer / chemistryPolyether ether ketone — a semi-crystalline polyaryletherketone[1]Polyethylene terephthalate glycol copolymer — PET with a glycol comonomer that suppresses crystallisation[2][3]
Densityg/cm³1.30 (ISO 1183)[1][4]1.24–1.30 (ISO 1183)[2][3][5][6]
Typical priceUSD/kg1 kg-equivalent spools span 296–770; the middle of the market is about 532[7][8][9]1 kg spools cluster near 20[10][11][12]
Price range across brandsUSD/kg296-770 across brands and spool sizes; 3D4Makers recycled R-PEEK 296 at 750 g, IEMAI 3D 420 at 1 kg, LEHVOSS Luvocom 3F PEEK 9581 532 at 2 kg, 3DXTech ThermaX PEEK 770 at 500 g[7][8][9]12–70 across brands; IEMAI 12, ELEGOO 14, CHCKX 14, Bambu Lab 18–20, Hatchbox 26, Prusament 38, Prusament PETG V0 70[10][11][13][12][14][15]
Market availability1–5Niche, a handful of specialist brands[7][8][4]Ubiquitous, every brand and retailer[10][11][16][12]
Spool sizes & diameters1.75 and 2.85 mm; 200 g to 2 kg spools[7][8][4]1.75 and 2.85 mm; 0.75, 0.8 and 1 kg spools plus spool-less refills[11][12]
Typical applicationsAerospace brackets, semiconductor handling, sterilisable medical tooling and downhole parts[1]Functional parts, enclosures and outdoor fittings that need more toughness and heat tolerance than PLA[2][3]
Diameter tolerance± mmNot documented±0.02 (Prusament)[2]
Printing Parameters
Nozzle temperature°C380-400 (3DXTech printed-specimen conditions); Victrex quotes a 340-450 melt range for AM 450 FIL[1][4]230–260 across brands; Prusament 250 ± 10, Polymaker 240–260[2][3][6]
Bed temperature°C130–140 (3DXTech)[1]60–90; Prusament 80 ± 10, Polymaker 60–70[2][6]
Enclosure / chamber requirement1–5Actively heated chamber required[17][18]Open frame is fine[6]
Recommended chamber temperature°CNot less than 150 for semi-crystalline printing (Victrex AM 450 FIL); bed above 150[4]Not documented
Part cooling fanNot documentedAround 50 %; Polymaker specifies 20–60 %, less than PLA to protect layer bonding[2][6]
Bed surface & adhesion aidNot documentedTextured PEI, satin or powder-coated sheets. On smooth PEI a glue stick is used as a release agent, not an adhesive — PETG bonds to bare PEI hard enough to tear the sheet[2][6]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sNot documented8–15 (PrusaSlicer guidance); My Tech Fun ran Bambu Lab PETG Basic at 13 mm³/s[19][20]
Warping tendency1–5Severe — heated chamber needed[17]Slight — corner lift on large flat parts[2][6]
Bed-adhesion difficulty1–5Very difficult — special plates or slurry required[17]Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[2]
Stringing / oozing tendency1–5Not documentedModerate — retraction tuning needed[2][6]
Overall printing difficulty1–5Expert / industrial hardware only[17][18]Easy — minor profile tuning[6]
Extruder requirementAn all-metal hot end rated above 400 °C and a heated chamber; 3DXTech tests at 0.25 mm layer height on a 0.4 mm nozzle[1][17]Not documented
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades, but brass softens near these nozzle temperatures — hardened or plated hot ends are the norm[17]Brass fine indefinitely[19]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive[6]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[21]Low — no special hot-end required and clogging is not among the listed drawbacks; Prusa lists no drybox and no hardened nozzle[22][23]
Heat-creep / jam sensitivity1–5Not documentedSlightly sensitive[22]
Hotend requirementNot documentedNo special hot-end required[22]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Not documentedModerate (0.3–0.8 %) — Bambu Lab reports 0.40 % saturated at 25 °C / 55 % RH; Prusa measures only 0.07 % in 24 h and 0.10 % in 7 days at the drier 22 % RH[2][24]
Equilibrium moisture content at ~50 % RH%0.45 at saturation, 23 °C (ISO 62); 0.55 at 100 °C[4]0.10 after 7 days at 24 °C / 22 % RH (Prusa Polymers); 0.40 saturated at 25 °C / 55 % RH (Bambu Lab)[2][24]
Drying temperature & time120 °C for 5 h, target below 0.020 % moisture (Victrex AM 450 FIL)[4]60–65 °C for 6–8 h[6][24]
Symptoms when wetNot documentedBubbling and popping at the nozzle, stringing and a rough surface[2]
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[21]Polymaker groups PETG with nylon, PVA and TPU as highly hygroscopic and shows a before-and-after-drying comparison; the loss appears as poor layer adhesion and weak, brittle layers rather than a published dry-versus-conditioned figure[25]
Storage requirementNot documentedSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[25][26]
Mechanical Properties
Tensile strength (XY)MPa60-100 (printed XY): Victrex AM 450 FIL 60-80 at yield and 3DXTech 100, both ISO 527; 98 at yield injection-moulded[1][4]38–51 (printed XY, ISO 527); Prusament 47 ± 2 at yield; 62 on My Tech Fun 4×4 mm bars[2][3][5][27]
Young's modulusMPa3000-4000 (printed XY, ISO 527, Victrex AM 450 FIL); 3720 (3DXTech); 4000 injection-moulded[1][4]1500–2311 (printed XY, ISO 527)[2][3][5][6]
Elongation at break%28 (printed XY, ISO 527) — remarkably ductile for a high-temperature polymer[1]5.2–9.3 at break (printed XY, ISO 527); Prusament 5.1 at yield[3][5][6][2]
Flexural strengthMPa130 (printed XY, ISO 178)[1]58–80 (printed XY, ISO 178); Prusament 66 ± 2[2][3][5][6]
Flexural modulusMPa2700 (printed XY, ISO 178)[1]1068–2277 (printed XY, ISO 178)[2][3][5][6]
Charpy impact, notchedkJ/m²6.0 (injection-moulded, ISO 179/1eA); unnotched does not break[4]2.6 (PolyLite) to 11.6 (PolyMax) printed XY, ISO 179, notched; Prusament 6 ± 1[3][5][2]
Other impact dataIzod notched 7.0 kJ/m2 injection-moulded (ISO 180/A). Printed anisotropy is extreme: VICTREX AM 200 on a Stratasys F900 gives Izod notched 1380-1530 J/m XZ against 30-62 J/m ZX (ASTM D256)[4][28]Charpy unnotched does not break on Prusa's 4 J pendulum (ISO 179-1); Izod 3.37 kJ/m² on My Tech Fun printed bars[2][27]
Layer adhesion / Z tensileMPa20-85 at yield (printed ZX, ISO 527, Victrex AM 450 FIL); the spread is set by chamber temperature and weld quality[4]18 ± 4 (Prusa interlayer adhesion test); 42.8 printed Z for PolyLite PETG; 33 on My Tech Fun bars[2][3][27]
Brittleness1–5Tough — absorbs impact, yields before breaking[1]Moderate[2][3]
Hardness (scale-specific)Shore A / Shore D / RockwellShore D 84.5 (injection-moulded, ISO 868); Rockwell M100 / R125 on extruded PEEK stock (ASTM D785)[4][29]74 Shore D (Prusa Polymers method); measured on printed bars at 68.2 for Extrudr PETG, 72 for Fiberlogy PETG and 72.8 for Prusament PETG[2][27][30][31]
Creep resistance / sustained load1–5Excellent — holds load for years. Victrex rates PEEK for long-term creep; injection-moulded flexural stress at 3.5 % strain falls only from 125 MPa at 23 °C to 85 MPa at 125 °C, and extruded stock is rated to 249 °C continuous[32][4][29]Below average — a 12 mm bar sagged to 18.2 mm (Fiberlogy) and 19.4 mm (Bambu Lab Basic) over 5 days at 1.25 kg[27][20]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable. Victrex rates PEEK for long-term fatigue as well as creep[32]Moderate — 79 000–193 000 cycles at 30 % of tensile strength, about three times printed PLA (R = 0.2, 7 Hz)[33]
Elasticity / flexibility1–5Rigid[1]Slightly flexible in thin sections[2]
Z strength as % of XY%71-84 (VICTREX AM 200 LMPAEK printed on the Stratasys F900 and Fortus 450mc, ZX against XZ tensile yield, ASTM D638); unfilled PEEK's own ZX spread is wider[28]84 (PolyLite, printed Z against XY tensile)[3]
Thermal Properties
HDT at 0.45 MPa°C140 (printed XY, ISO 75 at 0.45 MPa, 3DXTech)[1]68 (Prusament) to 78 (PolyLite), ISO 75 at 0.45 MPa[2][3][6]
HDT at 1.8 MPa°C152 (unannealed, ISO 75-2/Af, Victrex AM 450 FIL); 160 on extruded stock (ASTM D648 at 264 psi)[4][29]65 (Polymaker) to 75 (PolyLite), ISO 75 at 1.8 MPa; Prusament 68[2][3][6]
Glass transition (Tg)°C143 (DSC, 3DXTech); Victrex gives onset 143 and midpoint 150 (ISO 11357-2)[1][4]71–81 (DSC)[3][5][6]
Melting point / Vicat°C343 melting (ISO 11357-3, Victrex); VICTREX AM 200 LMPAEK melts at 303[4][28]Amorphous — no melting point; Vicat 75–84 (ISO 306)[3][5][6]
Continuous service temperature°C240 UL 746B relative thermal index, strength (RTI electrical 260, impact 180); Ensinger rates extruded PEEK stock at 249 long term[4][29]61–66 — loaded bars begin to move at this temperature across six grades from four brands; Prusa publishes 68 for Prusament PETG[27][30][31][20][34]
Thermal expansion (CTE)µm/m·K37.8 (extruded PEEK stock, 23-60 °C, ASTM E831; source states 2.1e-5 in/in/°F), rising to 41.9 at 60-100 °C and 55.8 at 100-150 °C[29]65 at 30 °C (neat PETG, large-format printed bead, TMA)[35]
Flammability / UL 94UL 94 V-0 at 1.5 mm on the base resin; glow-wire flammability index 960 °C at 2.0 mm (IEC 60695-2-12)[1][4]Flammable; no UL 94 rating published for standard PETG, though flame-retardant V0 grades exist[36][26]
Environment & Chemical
UV resistance1–5Not documentedModerate — a season or two[2]
Chemical resistanceOutstanding — resistant to almost all solvents and to steam sterilisation[1]Withstands acids, alkalis, oils and UV exposure — Polymaker names outdoor use as a result[26]
Water / humidity resistance in service1–5Excellent — essentially unaffected; 0.45 % water at saturation and resistant to steam sterilisation[4][1]Good — minor absorption[2]
Food contactNot documentedPET is the polymer of drinks bottles, but printed layer grooves harbour bacteria and no filament here carries a food-contact certification[26]
Biodegradability / compostabilityNot documentedNot biodegradable[26]
RecyclabilityNot documentedPET is widely recycled as bottle stock, but printed PETG waste is not accepted in household collection[26]
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[37]Moderate — measurable VOCs and UFPs, ventilation advised[37]
Ultrafine-particle emission rateparticles/minNot documented≈5 × 10⁹ median for the PET-based T-Glase filament in the same chamber study, against ≈1 × 10⁸ for PLA[37]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[37]Open a window / occasional ventilation[37]
Post-Processing
Sanding & machiningNot documentedSands poorly — the material is tough and gums rather than powders[22]
Painting & finishingNot documentedPaint adheres poorly without abrasion and a primer[2]
Gluing & solvent weldingNot documentedCyanoacrylate; no common solvent welds PETG cleanly[22]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing[2]
Support material pairingNot documentedPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[22]
Dimensional accuracy & detailNot documentedStringing and blobbing are the usual accuracy limits, not shrinkage[2][6]
Solvents & Solubility
Soluble in95–98 wt% sulphuric acid dissolves it — 10 g per 100 mL at 40–70 °C gives a dark red solution. Laboratory route only.[38][39]No common workshop solvent; 1,2-dichloroethane destroys it inside a week and dichloromethane — a carcinogen — dissolves the surface.[40][41]
Softened or crazed byConcentrated nitric, hydrofluoric, hydrobromic and hydriodic acids attack it; DCM, DMSO and THF swell thin-walled sections.[42][39]Acetone (+16 % weight over 1 year at 23 °C), ethyl acetate, toluene and DMF swell and soften it; methanol crazes it.[40]
Solvent welding & smoothing agentNone — no solvent softens PEEK, so parts are joined thermally or mechanically, never chemically.[42][39]Dichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[41]

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. ThermaX PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  2. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  3. PolyLite PETG Technical Data Sheet Polymaker Wiki · 2026-08 · tds
  4. VICTREX AM 450 FIL — datasheet Victrex · 2025-12 · tds
  5. PolyMax PETG Technical Data Sheet Polymaker Wiki · 2026-08 · tds
  6. Polymaker PETG Technical Data Sheet Polymaker Wiki · 2026-08 · tds
  7. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  8. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  9. IEMAI 3D PEEK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  10. PETG Basic — product page Bambu Lab US Store · 2026-08 · vendor
  11. Polymaker product catalogue Polymaker · 2026-08 · vendor
  12. Printed Solid product catalogue Printed Solid · 2026-08 · vendor
  13. Black PETG Filament 1.75 mm 1 kg — product data Hatchbox · 2026-08 · vendor
  14. IEMAI PETG 3D Printing Filament product page IEMAI 3D · 2026-08 · vendor
  15. CHCKX PETG 3D Printer Filament 1.75 mm 1 kg, Black CHCKX (Amazon US) · 2026-08 · vendor
  16. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  17. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  18. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  19. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  20. BambuLab PETG Basic vs Translucent vs PETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  21. ThermaX PEEK — product page 3DXTech · 2026-08 · vendor
  22. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  23. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  24. Bambu Filament Technical Data Sheet — PETG HF Bambu Lab · 2026-08 · tds
  25. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  26. PETG — material basics Polymaker Wiki · 2026-08 · doc
  27. PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  28. VICTREX AM 200 — FDM Material Data Sheet Stratasys · 2024-04 · tds
  29. TECAPEEK natural (PEEK) — stock shape properties Ensinger · 2026-08 · tds
  30. Extrudr PETG vs PCTG vs XPETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  31. Prusament PETG-CF vs PETG V0 vs PETG — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  32. PEEK polymers — product overview Victrex · 2026-08 · doc
  33. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  34. Prusament PETG — material page Prusa Polymers · 2026-08 · doc
  35. 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
  36. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  37. 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
  38. 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
  39. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  40. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  41. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  42. What solvents are not compatible with PEEK? — fluidics technical FAQ IDEX Health & Science · 2026-08 · doc