3D Printing Info

Filament comparison

PCTG vs PEI 9085

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

PCTG guidePEI (ULTEM 9085) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PCTG comparisonsMore PEI 9085 comparisons
PCTG vs PEI 9085 — documented properties and sources
PropertyPCTGPETGPEI (ULTEM 9085)HIGHTEMP
Market snapshot
Listing priceUSD/kg; dated snapshots$34.99/kg median; $14.00–$50.67/kg across 5 dated product listings$309.80/kg median; $220.00–$392.00/kg across 6 dated product listings
Identity & Market
Base polymer / chemistryPoly(cyclohexylenedimethylene terephthalate) glycol — a copolyester with a higher cyclohexanedimethanol content than PETG[1][2]Polyetherimide, ULTEM 9085 grade — the flame-retardant PEI used for aircraft interiors[3]
Densityg/cm³1.23 (Extrudr, ASTM D792; 3DXTech, ISO 1183)[2][4]1.34 (ISO 1183, 3DXTech) against 1.27 specific gravity on moulded plaques (ASTM D792, Stratasys) — the two suppliers disagree[3][5]
Typical priceUSD/kg1 kg spools cluster near 34[6][4][7]1 kg-equivalent spools cluster near 298[8][9][10][11]
Price range across brandsUSD/kg14–51 across brands; CHCKX 14 in a 10-roll bundle, Push Plastic 30, Proto-pasta 35 at 1 kg, 3DXTech 51[6][4][12]220-392 across brands and formats; 3DXTech ThermaX PEI 9085 220 at 2 kg, 3D4Makers 270 at 2 kg, Fiberlogy 298 at 500 g, Kimya 321 at 500 g, IEMAI 3D 385 at 1 kg, 3DXTech CarbonX PEI 9085+CF 392[8][9][10][11][13]
Market availability1–5Available from several mainstream brands[6][4][7][14]Niche, a handful of specialist brands[8][9][10][11]
Spool sizes & diameters1.75 and 2.85 mm; 0.5, 0.75, 1, 3 and 5 kg spools[6][7][4]1.75 and 2.85 mm; 250 g to 2 kg spools, plus Stratasys canisters[8][11][5]
Typical applicationsTransparent covers, guards and impact-loaded parts where PETG cracks[1][2]Aircraft interior parts and rail rolling stock, where the flame, smoke and toxicity rating is the requirement[3]
Printing Parameters
Nozzle temperature°C250–270 (Spectrum, Extrudr)[1][2]Not documented
Bed temperature°C60–100 (Spectrum)[1]130–140 (3DXTech)[3]
Enclosure / chamber requirement1–5Open frame is fine — Spectrum and Extrudr both say a closed chamber is not necessary, Extrudr adds it helps on larger parts[1][2]Actively heated chamber required[15][16]
Part cooling fanUp to 100 % (Spectrum); 20–50 % (Extrudr)[1][2]Not documented
Bed surface & adhesion aidTextured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[17][18]Not documented
Maximum volumetric flow (mm³/s; see test conditions)mm³/s1.6–16 at the 20–200 mm/s Extrudr rates the material for, on a 0.4 mm nozzle at 0.2 mm layer[2][19]Not documented
Warping tendency1–5Not documentedSevere — heated chamber needed[15]
Bed-adhesion difficulty1–5Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[17][18]Not documented
Stringing / oozing tendency1–5Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[18]Not documented
Shrinkage%0.2–0.5 (Extrudr, ASTM D955)[2]Not documented
Overall printing difficulty1–5Easy — minor profile tuning[1][2]Expert / industrial hardware only[15][16]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Extrudr explicitly states no hardened nozzle is needed[2]Brass fine indefinitely for unfilled grades, but brass softens near these nozzle temperatures — hardened or plated hot ends are the norm[15]
Abrasiveness1–5Non-abrasive[2]Non-abrasive when unfilled[3]
Nozzle clog risk1–5Low — 3DXTech lists no special nozzle concerns and no minimum layer height for PCTG, only a 65 °C pre-dry[20]Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[21]
Heat-creep / jam sensitivity1–5Slightly sensitive[22]Not documented
Hotend requirementNo special hot-end required[22]Not documented
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate (0.3–0.8 %) — the copolyester matrix reaches 0.40 % saturated at 25 °C / 55 % RH and 3DXTech specifies a 65 °C, 4 h pre-dry[17][20]Not documented
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface[23]Not documented
Effect of moisture on strengthPolymaker 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[23]No 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]
Storage requirementSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[23][18]Not documented
Mechanical Properties
Tensile strength (XY)MPa43–44 at yield and 45–46 at break (ISO 527, injection-moulded resin data from Spectrum and Extrudr); 48 on My Tech Fun printed bars[1][2][24]63-77 at break (printed XZ, ASTM D638, Stratasys F900/F3300/Fortus 450mc, three tips and two colours); 54 (printed XY, ISO 527, 3DXTech)[5][3]
Young's modulusMPaNot documented2040-2540 (printed XZ, ASTM D638, Stratasys); 2050 (printed XY, ISO 527, 3DXTech)[5][3]
Elongation at break%215–220 at break on moulded specimens (ISO 527); 4.3–4.4 at yield[1][2]5.4-9.1 at break (printed XZ, ASTM D638, Stratasys); 1.9-4.3 in ZX; 3DXTech quotes 3 (ISO 527)[5][3]
Flexural strengthMPaNot documented104-116 at break (printed XZ, ASTM D790 Procedure A, Stratasys); 72-98 in ZX; 3DXTech quotes 90 (ISO 178)[5][3]
Flexural modulusMPaNot documented2400-2550 (printed XZ, ASTM D790, Stratasys F900 T16 and T16A) against 2120-2130 in ZX; 3DXTech quotes 2170 (ISO 178)[5][3]
Charpy impact, notchedkJ/m²93–94 notched Izod at 23 °C on moulded specimens (ISO 180); 3DXTech quotes 8 by ISO 180/A[1][2][4]Not documented
Other impact dataIzod 4.14 kJ/m² on My Tech Fun printed bars, against 3.37 for PETG on the same rig[24]Izod notched 88.5-140 J/m XZ against 37-80 J/m ZX; unnotched 647-2260 J/m XZ against 169-633 J/m ZX (printed, ASTM D256/D4812, Stratasys, across three printers and three tips)[5]
Layer adhesion / Z tensileMPa21.6 on My Tech Fun 4×4 mm printed bars, against 32.9 for PETG[24]39-63 at break (printed ZX, ASTM D638, Stratasys); the low end is the F900 T16 baseline, the high end the F3300 N500 hot end[5]
Brittleness1–5Tough — absorbs impact, yields before breaking[1][2]Brittle — snaps with little warning[3]
Hardness (scale-specific)Shore A / Shore D / Rockwell69 Shore D measured by My Tech Fun, against 72 for PETG[24]Rockwell M110 / R126 on extruded PEI stock (ASTM D785)[25]
Creep resistance / sustained load1–5Below average — a 12 mm bar sagged to 19.4 mm over 5 days at 1.25 kg, slightly worse than PETG's 18.2[24]Excellent — holds load for years. Printed ZX coupons keep 87 % of room-temperature tensile strength at 104 °C and 70 % at 132 °C (ASTM D638); extruded PEI stock is rated 170 °C long-term service[5][25]
Fatigue / repeated-flex resistance1–5Good — 215 % elongation at break and 94 kJ/m² notched Izod on moulded specimens (Extrudr, Spectrum)[1][2]Not documented
Elasticity / flexibility1–5Slightly flexible in thin sections[24]Rigid[3]
Z strength as % of XY%Not documented56-86 (Stratasys ZX against XZ tensile at break, ASTM D638, across F900/F3300/Fortus 450mc and T16/T20/T40A tips); 58 on the F900 T16 baseline[5]
Thermal Properties
HDT at 0.45 MPa°CNot documented158 (printed XY, ISO 75 at 0.45 MPa, 3DXTech) to 178 (printed XY 178.2 and ZX 178.4, ASTM D648 Method B at 66 psi, Stratasys); moulded 176.9[3][5]
HDT at 1.8 MPa°CNot documented170-173 (printed XY 170.2 and ZX 172.6, ASTM D648 Method B at 264 psi); moulded 172.9[5]
Glass transition (Tg)°C78 (3DXTech, DSC)[4]177 (moulded plaque, ASTM D7426 inflection point, Stratasys); 186 (DSC, 3DXTech)[5][3][26]
Melting point / Vicat°CAmorphous — no melting point; Vicat 88 (Spectrum, Extrudr)[1][2]Not documented
Continuous service temperature°C68 — loaded bars begin to move at this temperature, against 65 for PETG[24]170 long-term service on extruded PEI stock, converted from 338 °F; 200 short term[25]
Thermal expansion (CTE)µm/m·KNot documented44.9 (printed XY, -50 to 80 °C, ASTM E831), falling to 31.4 over 80-160 °C; ZX gives 44.5 over -50 to 60 °C. Black pigment raises it to 51.9[5]
Flammability / UL 94Flammable; no UL 94 rating published for standard grades[27]UL 94 V-0 at 1.5 mm on the base resin. Printed parts are tested to 14 CFR 25.853, BSS 7238 and 7239 and AITM 2.0007B and 3.0005 covering 60 s and 12 s vertical burn, 15 s horizontal burn, smoke density, toxic gas emission and OSU heat release[3][5]
Environment & Chemical
UV resistance1–5Not documentedGood — years with some colour shift. 1000 h of QUV cycling to ASTM G154 left printed ZX coupons at 55.5 MPa yield against 56.0 unexposed, with elongation and modulus unchanged[5]
Chemical resistanceWithstands acids, alkalis, oils and UV exposure[18]Not documented
Water / humidity resistance in service1–5Good — minor absorption; Spectrum describes the polymer as hydrophobic[1]Not documented
Food contactNot certified for food contact as filament[18]Not documented
Biodegradability / compostabilityNot biodegradable[18]Not documented
RecyclabilityNot accepted in household plastic collection[18]Not documented
Electrical & ESD propertiesSurface resistance above 10¹³ ohm/sq — insulating (3DXTech, ASTM D257)[4]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[28]Moderate — 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[28]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[28]Ventilated room or enclosure recommended[28]
Post-Processing
Sanding & machiningSands poorly — the material is tough and gums rather than powders[22]Not documented
Gluing & solvent weldingCyanoacrylate; no common solvent welds PETG cleanly[22]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[22]Not documented
Support material pairingPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[22]Not documented
Dimensional accuracy & detailOptical clarity is the selling point; Extrudr recommends a layer height at most 50 % of nozzle diameter[2]Not documented
Solvents & Solubility
Soluble inNo common workshop solvent; Eastman's CHDM copolyester data shows 1,2-dichloroethane destroying it within a week.[29]Chlorinated hydrocarbons — dichloromethane and chloroform — are solvents for polyetherimide. Laboratory reagents.[30][31]
Softened or crazed byAcetone, ethyl acetate, toluene and DMF swell and soften the copolyester; methanol crazes it (Eastman, 1 y at 23 °C).[29]Acetone, MEK, benzene, toluene and butyl acetate craze or stress-crack it; alcohols, fuels and dilute acids do not.[31][30]
Solvent welding & smoothing agentDichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[32]Dichloromethane is the only welding route, and it is a controlled carcinogen rather than a workshop material.[30][31]

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. Spectrum Premium PCTG Technical Data Sheet Spectrum Filaments · 2026-08 · tds
  2. Extrudr PCTG technical data Extrudr · 2026-08 · tds
  3. ThermaX PEI 9085 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  4. MAX-G PCTG Technical Data Sheet 3DXTech · 2026-08 · tds
  5. ULTEM 9085 Resin — FDM Material Data Sheet Stratasys · 2026-04 · tds
  6. Push Plastic product catalogue Push Plastic · 2026-08 · vendor
  7. Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
  8. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  9. Kimya PEI-9085 Natural 2.85 mm 500 g igo3d · 2026-08 · vendor
  10. Fiberlogy PEI 9085 Natural, 1.75 mm / 500 g 3DJAKE · 2026-08 · vendor
  11. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  12. CHCKX 10KG Multicolor PCTG Filament bundle CHCKX (Amazon US) · 2026-08 · vendor
  13. IEMAI 3D PEI 9085 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  14. Atomic Filament product catalogue Atomic Filament · 2026-08 · vendor
  15. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  16. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  17. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  18. PETG — material basics Polymaker Wiki · 2026-08 · doc
  19. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  20. MAX-G PCTG — product page (print recommendations) 3DXTech · 2026-08 · doc
  21. THERMAX PEI 9085 — product page (print recommendations) 3DXTech · 2026-08 · doc
  22. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  23. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  24. PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  25. TECAPEI natural (PEI) — stock shape properties Ensinger · 2026-08 · tds
  26. ThermaX PEI 1010 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  27. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  28. 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
  29. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  30. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  31. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  32. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc