3D Printing Info

Filament comparison

PET-CF vs PLA Silk

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

Carbon-fibre PET (PET-CF) guideSilk PLA guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PET-CF comparisonsMore PLA Silk comparisons
PET-CF vs PLA Silk — documented properties and sources
PropertyCarbon-fibre PET (PET-CF)PETGSilk PLAPLA
Market snapshot
Listing priceUSD/kg; dated snapshots$39.99/kg median; $26.00–$49.98/kg across 4 dated product listings$19.49/kg median; $9.75–$24.99/kg across 15 dated product listings
Identity & Market
Base polymer / chemistrySemi-crystalline PET reinforced with carbon fibre — a different polymer from PETG-CF, with the glycol modifier removed so the matrix can crystallise[1][2]PLA with a gloss-forming additive package; suppliers publish the composition as polylactic acid only[3]
Densityg/cm³1.29 (Bambu Lab) and 1.34 (Fiberon PET-CF17), ISO 1183[1][2]1.27 (ISO 1183)[3]
Typical priceUSD/kg1 kg spools cluster near 45[1][4]Mainstream 1 kg spools cluster near 20[5][6][7]
Price range across brandsUSD/kg26–50 across brands; ELEGOO 26 in a 5 kg pack, Bambu Lab 45, Fiberon 50[8][1][4]10–25 across brands; CHCKX 10 in a 16-roll bundle, SUNLU 13, LANDU 18, YXPOLYER 20, Polymaker 22, Devil Design 25[9][10][11][12][13]
Market availability1–5Available from several mainstream brands[1][4][8]Stocked by most mainstream brands[5][9][14]
Spool sizes & diameters1.75 mm; 0.5 and 1 kg spools[4][1]1.75 mm; 1 and 1.1 kg spools; dual- and tri-colour coextruded variants[15][16]
Typical applicationsLoad-bearing parts that must survive above PETG's 70 °C ceiling without moving to PA or PC[1][2]Decorative prints where surface gloss matters more than strength[3]
Diameter tolerance± mmNot documented±0.03 (Bambu Lab)[17]
Printing Parameters
Nozzle temperature°C260–290 (Bambu Lab)[1]210–240 — 20 °C above the plain PLA window[3]
Bed temperature°C80–100 (Bambu Lab)[1]35–45[3]
Enclosure / chamber requirement1–5Enclosure recommended — Bambu Lab specifies a 45–60 °C chamber[1]Open frame is fine[3][18]
Recommended chamber temperature°C45–60 (Bambu Lab)[1]Not documented
Part cooling fan0–60 % (Bambu Lab)[1]Fan on[3]
Bed surface & adhesion aidTextured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[19][20]Cool Plate SuperTack, smooth PEI or textured PEI[3]
Maximum volumetric flow (mm³/s; see test conditions)mm³/s8 at Bambu Lab's 100 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer — half the speed it allows for PETG-CF[1][21]Not documented
Warping tendency1–5Not documentedNone[3]
Bed-adhesion difficulty1–5Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[19][20]Sticks to anything[22]
Stringing / oozing tendency1–5Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[20]Not documented
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning[1]Easy — minor profile tuning; hotter nozzle and slower cap of 250 mm/s[3]
Hardware Wear & Reliability
Nozzle hardness required1–4Hardened steel required[1]Brass fine indefinitely[18]
Abrasiveness1–5Highly abrasive — standard CF composite[1]Non-abrasive[23][18]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle; Prusa lists higher risk of nozzle clogging for carbon-filled composites[24]Very low[18]
Heat-creep / jam sensitivity1–5Slightly sensitive[25]Moderate — good heatbreak cooling needed; PLA softens below 60 °C[26]
Hotend requirementNo special hot-end required[25]No special hot-end required[22]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate — 0.37 % saturated at 25 °C / 55 % RH (Bambu Lab); 0.53 % equilibrium (Fiberon)[1][2]Moderate — 0.40 % saturated at 25 °C / 55 % RH[3]
Equilibrium moisture content at ~50 % RH%0.37 saturated at 25 °C / 55 % RH (Bambu Lab); 0.53 equilibrium (Fiberon PET-CF17)[1][2]0.40 saturated at 25 °C / 55 % RH (Bambu Lab)[3]
Drying temperature & time80 °C for 8–12 h (Bambu Lab) — the longest and hottest dry in the polyester family; Fiberon specifies 100 °C for 10 h[1][2]55 °C for 8 h in a forced-air dryer, or 65–75 °C for 12 h on an X1 heatbed[3][27]
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface[28]Bubbling and popping at the nozzle, stringing, rough surface and weak layers[28]
Effect of moisture on strengthBambu Lab publishes its whole mechanical table under the heading "Mechanical Properties (Dry state)" — the quoted figures apply only to dried filament[1]Polymaker rates PLA low-sensitivity — the loss shows as poor layer adhesion and brittle layers rather than a published strength figure[28]
Storage requirementSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[28][20]Sealed with desiccant below 20 % RH; shelf life at ambient is long[29][22]
Hydrolysis at melt temperatureThe 80–100 °C dry both suppliers mandate is far above the 55–65 °C used for PETG, consistent with a melt-hydrolysis risk in the semi-crystalline PET matrix; neither publishes a molecular-weight loss figure[1][2]Not documented
Mechanical Properties
Tensile strength (XY)MPa65.9 (Fiberon) to 74 (Bambu Lab) printed XY, ISO 527[1][2]33 (printed XY, ISO 527); eSun Silk broke 22 % below the 16-brand PLA mean on identical 4×4 mm bars[3][30]
Young's modulusMPa4730 ± 260 (Bambu Lab) and 5481 ± 224 (Fiberon) printed XY, ISO 527[1][2]2130 (printed XY, ISO 527)[3]
Elongation at break%2.4 ± 0.5 printed XY, ISO 527 (Fiberon PET-CF17)[2]2.8 (printed XY, ISO 527) — a quarter of PLA Basic at 12.2[3][29]
Flexural strengthMPa109.3 ± 2.0 printed XY, ISO 178 (Fiberon PET-CF17)[2]75 (printed XY, ISO 178)[3]
Flexural modulusMPa4744 ± 136 printed XY, ISO 178 (Fiberon PET-CF17)[2]2460 (printed XY, ISO 178)[3]
Charpy impact, notchedkJ/m²5.1 ± 0.2 printed XY, ISO 179 notched (Fiberon PET-CF17); unnotched 25.1 ± 2.8[2]10.3 (printed XY, ISO 179, notched); unnotched 18.5[3]
Layer adhesion / Z tensileMPa27.9 (Fiberon) and 35 ± 5 (Bambu Lab) printed Z, ISO 527[1][2]25 (printed Z, ISO 527), and flexural Z collapses to 30 against 75 in XY; eSun Silk broke at 12.3 kg where twelve of the 16 plain PLAs managed 44.6–61.5 kg[3][30][31]
Brittleness1–5Very brittle — elongation at break 2.4 % in XY and 0.8 % in Z[2]Brittle — snaps with little warning[3]
Creep resistance / sustained load1–5Good — no creep test found; annealed PET-CF holds a 105 °C HDT at 1.8 MPa and a 4730–5481 MPa modulus against 1500–2311 for PETG[2][1]Poor — no silk-specific creep data published; plain PLA sagged from 12 to 18.7–20.3 mm over 5 days at 1.25 kg[32][33]
Fatigue / repeated-flex resistance1–5Below average — no S-N curve; elongation at break is 2.4 % in XY and 0.8 % in Z, against 5.2–9.3 % for unfilled PETG[2]Poor — no grade-specific S-N curve; plain printed PLA ran 38 000–49 000 cycles at 30 % of tensile strength (R = 0.2)[34][26]
Elasticity / flexibility1–5Rigid[1]Rigid[3]
Z strength as % of XY%42 (Fiberon) to 47 (Bambu Lab), printed[1][2]76 by tensile, 40 by flexural (printed, Bambu Lab)[3]
Thermal Properties
HDT at 0.45 MPa°C147.5 (Fiberon) and 205 (Bambu Lab), ISO 75 at 0.45 MPa[1][2]60 (ISO 75, 0.45 MPa)[3]
HDT at 1.8 MPa°C105 (Fiberon) and 182 (Bambu Lab), ISO 75 at 1.8 MPa[1][2]56 (ISO 75, 1.8 MPa)[3]
Glass transition (Tg)°C75 (Bambu Lab) and 79.3 (Fiberon), DSC[1][2]57 (DSC)[3]
Melting point / Vicat°C241.3 (Fiberon) and 250 (Bambu Lab) melting, DSC; Vicat 226–238[1][2]158 peak melt (DSC); Vicat 66 °C[3]
Continuous service temperature°CNot documented50 — a loaded bar begins to move at this temperature (My Tech Fun, eSun eSilk PLA)[31]
Annealing responseThe PET matrix crystallises on annealing, which is what separates this grade from PETG-CF[2][1]50–55 °C for 6–12 h[3]
Flammability / UL 94Flammable; no UL 94 rating published for standard grades[35]Flammable; no UL 94 rating published by the major brands[29][36]
Environment & Chemical
UV resistance1–5Not documentedDegrades within weeks outdoors[26][37]
Chemical resistanceWithstands acids, alkalis, oils and UV exposure[20]Good against weak acids, oils and grease; poor against strong acids and alkalis; dissolved by chloroform, THF and hot benzene[36][26]
Water / humidity resistance in service1–5Not documentedGood — insoluble in water[29]
Food contactNot certified for food contact as filament[20]Base resin is food-contact grade, but printed layer grooves harbour bacteria; Prusa advises against food use[26]
Biodegradability / compostabilityNot biodegradable[20]Industrially compostable only — needs sustained 55 °C; not home compostable[38][26]
RecyclabilityNot accepted in household plastic collection[20]Mechanically recyclable; not accepted in household plastic collection[38]
Electrical & ESD propertiesSurface resistivity above 10¹² ohm — insulating (Fiberon PET-CF17, ANSI/ESD S11.11)[2]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[39]Low hazard — minimal VOC and particle emission[39]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[39][1]None needed in a normal room[39]
Dust & fibre handling hazardCarbon fibre is bound in the matrix; sanding dust should not be inhaled[2]Not documented
Post-Processing
Sanding & machiningSands poorly — the material is tough and gums rather than powders[25]Wet sanding — dry sanding heats the surface by friction and smears it[37][26]
Gluing & solvent weldingCyanoacrylate; no common solvent welds PETG cleanly[25]Cyanoacrylate for most joints; some grades partially dissolve and bond with acetone[26][40]
Vapour / chemical smoothingNo practical vapour smoothing[25]No practical vapour smoothing — only chloroform, hot benzene or THF, which are laboratory-only[26]
Support material pairingPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[25]Support for PLA (Bambu Lab)[3]
Dimensional accuracy & detailBambu Lab markets it on low warping and shrinkage relative to other high-temperature composites[1]55° overhangs and 30 mm bridges; gloss hides fine detail and is destroyed by sanding[3]
Solvents & Solubility
Soluble inNone common; fluorinated solvents such as hexafluoroisopropanol dissolve linear polyester at 23 °C. Laboratory only.[41][42]Chloroform: 10 % w/v in 2–4 h at 23 °C, every grade and morphology; THF and DMF only at 65 °C. Laboratory reagents.[43]
Softened or crazed byEnsinger rates polyester not resistant to chloroform or dichloromethane and only conditionally resistant to acetone and MEK.[42]Acetone, ethyl acetate and toluene plasticise it but dissolve <1 % even at 65 °C; submersion in acetone crazes and destroys parts.[43][44]
Solvent welding & smoothing agentDichloromethane attacks polyester and can be brushed on, but the carbon fibre blocks any useful surface flow.[42][44]Chloroform vapour smooths and welds PLA at the cost of tensile strength; acetone does not smooth it at all.[45][44]

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 — PET-CF Bambu Lab · 2026-08 · tds
  2. Fiberon PET-CF17 Technical Data Sheet V1.0 Polymaker · 2026-08 · tds
  3. Bambu Filament Technical Data Sheet V1.0 — PLA Silk+ Bambu Lab · 2026-08 · tds
  4. Polymaker product catalogue Polymaker · 2026-08 · vendor
  5. Panchroma Silk PLA collection Polymaker Shop · 2026-08 · vendor
  6. Spectrum PLA Silk — product listing 3DJake International · 2026-08 · vendor
  7. 3DJake ecoPLA Silk Black 1.75mm 1000g 3DJake International · 2026-08 · vendor
  8. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  9. Sunlu Silk PLA+ 1.75mm 1kg Sunlu Official Store · 2026-08 · vendor
  10. Bambu Lab PLA Silk 1.75mm 1kg 3D Universe · 2026-08 · vendor
  11. CHCKX 16 Pack Silk Dual Color PLA Filament Bundle CHCKX (Amazon US) · 2026-08 · vendor
  12. YXPOLYER Silk PLA Black&Gold product page YXPOLYER · 2026-08 · vendor
  13. LANDU Silk Tri-Color PLA Filament 1.75 mm 1 kg LANDU (Amazon US) · 2026-08 · vendor
  14. Overture Silk PLA 1.75mm Overture3D · 2026-08 · vendor
  15. eSUN PLA-Silk Magic 1.75mm eSUN Official Store · 2026-08 · vendor
  16. JAYO Silk PLA+ 1.75mm 1.1kg JAYO Official Store · 2026-08 · vendor
  17. PLA Basic — product page Bambu Lab US Store · 2026-08 · vendor
  18. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  19. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  20. PETG — material basics Polymaker Wiki · 2026-08 · doc
  21. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  22. PLA — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  23. Prusament PLA — material page Prusa Polymers · 2026-08 · doc
  24. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  25. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  26. PLA — material guide Prusa Knowledge Base · 2026-08 · doc
  27. Filament Drying Recommendations Bambu Lab Wiki · 2026-08 · doc
  28. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  29. Bambu Filament Technical Data Sheet V3.0 — PLA Basic Bambu Lab · 2026-08 · tds
  30. 16 PLA brand comparison test — results spreadsheet My Tech Fun (Igor Gaspar) · 2022-10 · test
  31. Testing eSun PLA filaments: PLA-ST vs PLA+ vs Silk PLA My Tech Fun (Igor Gaspar) · 2026-08 · test
  32. BambuLab PLA Basic vs PLA Tough vs PLA-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  33. PolyTerra PLA vs PLA+ — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  34. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  35. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  36. PolyLite PLA Technical Data Sheet V5.4 Polymaker · 2024-11 · tds
  37. Prusament PLA Technical Data Sheet v1.0 Prusa Polymers · 2018-09 · tds
  38. Filamentive PLA (recycled) — product page Filamentive · 2026-08 · vendor
  39. 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
  40. Prusament rPLA Corn Pigment 1kg — product page Prusa Research · 2026-08 · vendor
  41. Resistance of Ultramid, Ultraform and Ultradur to chemicals (TI-KTU/AS-28 e) BASF · 2000-10 · tds
  42. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  43. Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
  44. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  45. Effect of vapour smoothing in trichloromethane on 3D printed PLA — surface, mechanical and chemical structure Pitale, Keche & Chopra, Engineering Research Express 6(4) 045579 · 2024-12 · paper