3D Printing Info

Filament comparison

e-TPU vs PETG

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

Foaming / expanded TPU (TPU Aero / TPU Air) guidePETG guide

2 selected · all documented properties

Open these two in the interactive comparisonMore e-TPU comparisonsMore PETG comparisons
e-TPU vs PETG — documented properties and sources
PropertyFoaming / expanded TPU (TPU Aero / TPU Air)FLEXPETGPETG
Market snapshot
Listing priceUSD/kg; dated snapshots$52.05/kg median; $41.99–$85.29/kg across 6 dated product listings$19.99/kg median; $8.99–$69.99/kg across 21 dated product listings
Identity & Market
Base polymer / chemistryFoaming thermoplastic polyurethane — a blowing agent expands the extrudate so the printed Shore hardness can be tuned by flow rate[1]Polyethylene terephthalate glycol copolymer — PET with a glycol comonomer that suppresses crystallisation[2][3]
Densityg/cm³1.15 filament (Siraya Tech Flex TPU Air) and 1.05 (Roamr TPU Air HR), ISO 1183; the printed part falls to 0.51–0.93 depending on nozzle temperature (ISO 845)[4][5]1.24–1.30 (ISO 1183)[2][3][6][7]
Typical priceUSD/kg1 kg-equivalent spools span 42–85; the middle of the market is about 52[8][9][10][11][12][13]1 kg spools cluster near 20[14][15][16]
Price range across brandsUSD/kg42–85 across brands; QIDI TPU-Aero 42, Siraya Tech Flex TPU Air 45, Phaetus aeFlex TPU-Aero 49 direct and 40 at West3D, Roamr TPU Air HR 80A 55 at 800 g, Recreus Filaflex Foamy 73 at 750 g, colorFabb varioShore 85 at 700 g[8][9][10][11][12][13][17]12–70 across brands; IEMAI 12, ELEGOO 14, CHCKX 14, Bambu Lab 18–20, Hatchbox 26, Prusament 38, Prusament PETG V0 70[14][15][18][16][19][20]
Market availability1–5Available from several mainstream brands — colorFabb, Recreus, QIDI, Phaetus, Siraya Tech and FusRock all sell an active-foaming TPU[1][8][9][10][12][13]Ubiquitous, every brand and retailer[14][15][21][16]
Spool sizes & diameters1.75 mm; 0.7, 0.75, 0.8, 1 and 3 kg spools[1][8][10][11][13]1.75 and 2.85 mm; 0.75, 0.8 and 1 kg spools plus spool-less refills[15][16]
Typical applicationsCushioning, midsoles, insoles and soft-touch parts where the softness needs to vary within one print; Siraya Tech's Roamr line is aimed specifically at printed footwear[1][11]Functional parts, enclosures and outdoor fittings that need more toughness and heat tolerance than PLA[2][3]
Diameter tolerance± mm0.03 (Siraya Tech and Roamr, 1.75 mm)[4][5]±0.02 (Prusament)[2]
Printing Parameters
Nozzle temperature°C230–270 (QIDI and Siraya Tech), 220–260 (Roamr); foaming activates near 230 °C and is strongest at the top of the range[1][4][5][12]230–260 across brands; Prusament 250 ± 10, Polymaker 240–260[2][3][7]
Bed temperature°C30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[4][5][12]60–90; Prusament 80 ± 10, Polymaker 60–70[2][7]
Enclosure / chamber requirement1–5Open frame is fine — Roamr states no enclosure is required[1][5]Open frame is fine[7]
Part cooling fan100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[4][5]Around 50 %; Polymaker specifies 20–60 %, less than PLA to protect layer bonding[2][7]
Bed surface & adhesion aidPEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent, and Siraya Tech recommends PVP glue or Magigoo as a release agent on PEI[22][23][4]Textured 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][7]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sUp to 12 (Siraya Tech, Flex TPU Air)[10]8–15 (PrusaSlicer guidance); My Tech Fun ran Bambu Lab PETG Basic at 13 mm³/s[24][25]
Warping tendency1–5Not documentedSlight — corner lift on large flat parts[2][7]
Bed-adhesion difficulty1–5Not documentedNeeds the right surface or a thin adhesive — the problem is releasing the part, not sticking it[2]
Stringing / oozing tendency1–5Severe — the material expands inside the hot end, so it oozes on travel moves; QIDI states retraction tuning cannot fix it and Siraya Tech advises setting retraction distance and speed to zero[4][12]Moderate — retraction tuning needed[2][7]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; both density and hardness follow nozzle temperature and flow[1]Easy — minor profile tuning[7]
Extruder requirementDirect drive; the base material is a 92A TPU[1][26]Not documented
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[27][5]Brass fine indefinitely[24]
Abrasiveness1–5Non-abrasive[27]Non-abrasive[7]
Nozzle clog risk1–5Not documentedLow — no special hot-end required and clogging is not among the listed drawbacks; Prusa lists no drybox and no hardened nozzle[28][29]
Heat-creep / jam sensitivity1–5Not documentedSlightly sensitive[28]
Hotend requirementNo special hot-end required, but a direct-drive extruder is (Simplify3D)[22]No special hot-end required[28]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate[30]Moderate (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][31]
Equilibrium moisture content at ~50 % RH%1.09 water absorption (QIDI TPU-Aero; the standard is not stated)[12]0.10 after 7 days at 24 °C / 22 % RH (Prusa Polymers); 0.40 saturated at 25 °C / 55 % RH (Bambu Lab)[2][31]
Drying temperature & time70–80 °C for 4–6 h; keep below 15 % RH while printing (Siraya Tech, Roamr and QIDI)[4][5][12]60–65 °C for 6–8 h[7][31]
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface; Siraya Tech adds that moisture wrecks the foaming itself, not only the surface[30][4]Bubbling and popping at the nozzle, stringing and a rough surface[2]
Effect of moisture on strengthPolymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[30]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[30]
Storage requirementSealed with desiccant; often kept in a dryer during the print[30]Sealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[30][32]
Mechanical Properties
Tensile strength (XY)MPaFalls with foaming: colorFabb 24 unfoamed and 12 foamed (ISO 527-1A); Siraya Tech 10.3 at break printed at 240 °C down to 3.8 at 270 °C; QIDI 6.81 at break (ISO 527, XY)[1][4][12]38–51 (printed XY, ISO 527); Prusament 47 ± 2 at yield; 62 on My Tech Fun 4×4 mm bars[2][3][6][33]
Young's modulusMPa50 unfoamed and 40 foamed (colorFabb, ISO 527-1A)[1]1500–2311 (printed XY, ISO 527)[2][3][6][7]
Elongation at break%465 unfoamed and 450 foamed (colorFabb, ISO 527-1A); Siraya Tech 629 at 240 °C down to 475 at 270 °C; Roamr 760 down to 540; QIDI 576 (ISO 527, XY)[1][4][5][12]5.2–9.3 at break (printed XY, ISO 527); Prusament 5.1 at yield[3][6][7][2]
Flexural strengthMPaNot documented58–80 (printed XY, ISO 178); Prusament 66 ± 2[2][3][6][7]
Flexural modulusMPa50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[1]1068–2277 (printed XY, ISO 178)[2][3][6][7]
Charpy impact, notchedkJ/m²Not documented2.6 (PolyLite) to 11.6 (PolyMax) printed XY, ISO 179, notched; Prusament 6 ± 1[3][6][2]
Other impact dataNot documentedCharpy 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][33]
Layer adhesion / Z tensileMPaNot documented18 ± 4 (Prusa interlayer adhesion test); 42.8 printed Z for PolyLite PETG; 33 on My Tech Fun bars[2][3][33]
Brittleness1–5Very ductile — bends far before failing[1]Moderate[2][3]
Hardness (scale-specific)Shore A / Shore D / RockwellTunable by nozzle temperature: colorFabb 92 Shore A unfoamed; Siraya Tech 78 A printed at 240 °C falling to 63 A at 270 °C, Roamr TPU Air HR 80A 80 A down to 66 A and HR 85A 83 A down to 70 A (ISO 7619)[1][4][5][34]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][33][35][36]
Creep resistance / sustained load1–5Poor — no foamed-grade creep test; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[37]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[33][25]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[23]Moderate — 79 000–193 000 cycles at 30 % of tensile strength, about three times printed PLA (R = 0.2, 7 Hz)[38]
Elasticity / flexibility1–5Rubbery / highly elastic[1]Slightly flexible in thin sections[2]
Z strength as % of XY%Not documented84 (PolyLite, printed Z against XY tensile)[3]
Thermal Properties
HDT at 0.45 MPa°CNot documented68 (Prusament) to 78 (PolyLite), ISO 75 at 0.45 MPa[2][3][7]
HDT at 1.8 MPa°CNot documented65 (Polymaker) to 75 (PolyLite), ISO 75 at 1.8 MPa; Prusament 68[2][3][7]
Glass transition (Tg)°CNot documented71–81 (DSC)[3][6][7]
Melting point / Vicat°CVicat softening drops as the foam expands: 83 printed at 240 °C to 53 at 270 °C (Siraya Tech, ISO 306); QIDI 70.4[4][12]Amorphous — no melting point; Vicat 75–84 (ISO 306)[3][6][7]
Continuous service temperature°CNot documented61–66 — loaded bars begin to move at this temperature across six grades from four brands; Prusa publishes 68 for Prusament PETG[33][35][36][25][39]
Annealing responseFoaming activates near 230 °C and expands the extrudate about 1.6×; colorFabb advises dropping flow to 60–70 % to realise the weight saving, and Siraya Tech publishes a flow schedule from 85–90 % at 230 °C down to 50–55 % at 270 °C[1][4]Not documented
Thermal expansion (CTE)µm/m·KNot documented65 at 30 °C (neat PETG, large-format printed bead, TMA)[40]
Flammability / UL 94Not documentedFlammable; no UL 94 rating published for standard PETG, though flame-retardant V0 grades exist[41][32]
Environment & Chemical
UV resistance1–5Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[23]Moderate — a season or two[2]
Chemical resistanceWithstands industrial solvents and UV exposure (Polymaker)[23]Withstands acids, alkalis, oils and UV exposure — Polymaker names outdoor use as a result[32]
Water / humidity resistance in service1–5Not documentedGood — minor absorption[2]
Food contactNot food safe without specific certification (Polymaker)[23]PET is the polymer of drinks bottles, but printed layer grooves harbour bacteria and no filament here carries a food-contact certification[32]
Biodegradability / compostabilityNot biodegradable[23]Not biodegradable[32]
RecyclabilityNot accepted in household plastic collection[23]PET is widely recycled as bottle stock, but printed PETG waste is not accepted in household collection[32]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[42]Moderate — measurable VOCs and UFPs, ventilation advised[42]
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[42]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[42]Open a window / occasional ventilation[42]
Post-Processing
Sanding & machiningDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[23]Sands poorly — the material is tough and gums rather than powders[28]
Painting & finishingNot documentedPaint adheres poorly without abrasion and a primer[2]
Gluing & solvent weldingCyanoacrylate bonds TPU; no common solvent welds it[23]Cyanoacrylate; no common solvent welds PETG cleanly[28]
Vapour / chemical smoothingNo practical vapour smoothing[23]No practical vapour smoothing[2]
Support material pairingPolymaker warns TPU supports are often very difficult to remove[23]Prints its own supports; Polymaker rates PolyDissolve S1 for PETG[28]
Dimensional accuracy & detailFoamed surfaces are matte and textured; holding a consistent hardness means holding the nozzle temperature steady, and the printed density moves by nearly a factor of two across the 230–270 °C window[1][4]Stringing and blobbing are the usual accuracy limits, not shrinkage[2][7]
Solvents & Solubility
Soluble inDMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[43]No common workshop solvent; 1,2-dichloroethane destroys it inside a week and dichloromethane — a carcinogen — dissolves the surface.[44][45]
Softened or crazed byToluene and benzene swell it up to +50 % by weight at 23 °C; the foamed wall soaks up esters and alcohols faster still.[43]Acetone (+16 % weight over 1 year at 23 °C), ethyl acetate, toluene and DMF swell and soften it; methanol crazes it.[44]
Solvent welding & smoothing agentNone practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[43]Dichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[45]

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. varioShore TPU Technical Data Sheet colorFabb · 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. Siraya Tech Flex TPU Air Technical Data Sheet Siraya Tech · 2026-08 · tds
  5. Roamr TPU Air HR 80A Technical Data Sheet Siraya Tech · 2026-08 · tds
  6. PolyMax PETG Technical Data Sheet Polymaker Wiki · 2026-08 · tds
  7. Polymaker PETG Technical Data Sheet Polymaker Wiki · 2026-08 · tds
  8. Recreus product catalogue Recreus · 2026-08 · vendor
  9. varioShore TPU Natural — product page colorFabb US · 2026-08 · vendor
  10. Siraya Tech Flex TPU Air Black Filament — lightweight foaming flexible, product page Siraya Tech · 2026-08 · vendor
  11. Roamr TPU Air HR 80A Filament — product page Siraya Tech · 2026-08 · vendor
  12. TPU-Aero Lightweight TPU Filament — product page with specification tables QIDI Tech · 2026-08 · vendor
  13. aeFlex TPU-Aero — active foaming low weight TPU, product page Phaetus · 2026-08 · vendor
  14. PETG Basic — product page Bambu Lab US Store · 2026-08 · vendor
  15. Polymaker product catalogue Polymaker · 2026-08 · vendor
  16. Printed Solid product catalogue Printed Solid · 2026-08 · vendor
  17. Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
  18. Black PETG Filament 1.75 mm 1 kg — product data Hatchbox · 2026-08 · vendor
  19. IEMAI PETG 3D Printing Filament product page IEMAI 3D · 2026-08 · vendor
  20. CHCKX PETG 3D Printer Filament 1.75 mm 1 kg, Black CHCKX (Amazon US) · 2026-08 · vendor
  21. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  22. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  23. TPU — material basics Polymaker Wiki · 2026-08 · doc
  24. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  25. BambuLab PETG Basic vs Translucent vs PETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  26. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  27. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  28. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  29. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  30. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  31. Bambu Filament Technical Data Sheet — PETG HF Bambu Lab · 2026-08 · tds
  32. PETG — material basics Polymaker Wiki · 2026-08 · doc
  33. PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  34. Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
  35. Extrudr PETG vs PCTG vs XPETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  36. Prusament PETG-CF vs PETG V0 vs PETG — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  37. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  38. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  39. Prusament PETG — material page Prusa Polymers · 2026-08 · doc
  40. 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
  41. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  42. 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
  43. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  44. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  45. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc