3D Printing Info

Filament comparison

PLA Silk vs TPU soft

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

Silk PLA guideSoft TPU (below 85A) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PLA Silk comparisonsMore TPU soft comparisons
PLA Silk vs TPU soft — documented properties and sources
PropertySilk PLAPLASoft TPU (below 85A)FLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$19.49/kg median; $9.75–$24.99/kg across 15 dated product listings$114.04/kg median; $109.80–$122.27/kg across 4 dated product listings
Identity & Market
Base polymer / chemistryPLA with a gloss-forming additive package; suppliers publish the composition as polylactic acid only[1]Very soft thermoplastic elastomers below 85 Shore A. Fiberlogy's FiberFlex 30D measures 81 Shore A, the softest grade with a published datasheet found here[2]
Densityg/cm³1.27 (ISO 1183)[1]1.07 (Fiberlogy FiberFlex 30D, ISO 1183)[2]
Typical priceUSD/kgMainstream 1 kg spools cluster near 20[3][4][5]1 kg-equivalent spools cluster near 115[6][7][8]
Price range across brandsUSD/kg10–25 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]110–122 at 1 kg-equivalent; Recreus 70A 110 and 60A 116 at 500 g, NinjaTek Edge 83A 112, NinjaTek Chinchilla 75A 122; the Recreus 3 kg spools fall to 70–73[6][8][7]
Market availability1–5Stocked by most mainstream brands[3][9][14]Niche, a handful of specialist brands[2][15][6]
Spool sizes & diameters1.75 mm; 1 and 1.1 kg spools; dual- and tri-colour coextruded variants[16][17]1.75, 2.85 and 3 mm; 0.5, 0.85, 1, 2 and 3 kg spools[2][6][18][7]
Typical applicationsDecorative prints where surface gloss matters more than strength[1]Highly compliant seals, soft grips and prosthetic liners[2]
Diameter tolerance± mm±0.03 (Bambu Lab)[19]Not documented
Printing Parameters
Nozzle temperature°C210–240 — 20 °C above the plain PLA window[1]Not documented
Bed temperature°C35–45[1]50–70 (Fiberlogy FiberFlex 30D)[2]
Enclosure / chamber requirement1–5Open frame is fine[1][20]Open frame is fine[2]
Part cooling fanFan on[1]Not documented
Bed surface & adhesion aidCool Plate SuperTack, smooth PEI or textured PEI[1]PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[21][22]
Warping tendency1–5None[1]Not documented
Bed-adhesion difficulty1–5Sticks to anything[23]Not documented
Overall printing difficulty1–5Easy — minor profile tuning; hotter nozzle and slower cap of 250 mm/s[1]Expert / industrial hardware only — below 85 Shore A the filament buckles in almost any feed path that is not a short, constrained direct drive[18][22]
Extruder requirementNot documentedDirect drive only, with a constrained filament path; Bowden is not viable at this hardness[18][15]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely[20]Brass fine indefinitely[24]
Abrasiveness1–5Non-abrasive[25][20]Non-abrasive[24]
Nozzle clog risk1–5Very low[20]High — jams from moisture, heat creep or particles; below 85 Shore A the filament buckles and compresses, and Simplify3D warns that raised feed rates most likely end in a jam[21][22][26]
Heat-creep / jam sensitivity1–5Moderate — good heatbreak cooling needed; PLA softens below 60 °C[27]Very high — softens in the cold zone readily[22]
Hotend requirementNo special hot-end required[23]No special hot-end required, but a direct-drive extruder is (Simplify3D)[21]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate — 0.40 % saturated at 25 °C / 55 % RH[1]Moderate[26]
Equilibrium moisture content at ~50 % RH%0.40 saturated at 25 °C / 55 % RH (Bambu Lab)[1]Not documented
Drying temperature & time55 °C for 8 h in a forced-air dryer, or 65–75 °C for 12 h on an X1 heatbed[1][28]Not documented
Symptoms when wetBubbling and popping at the nozzle, stringing, rough surface and weak layers[26]Bubbling and popping at the nozzle, stringing and a rough surface[26]
Effect of moisture on strengthPolymaker rates PLA low-sensitivity — the loss shows as poor layer adhesion and brittle layers rather than a published strength figure[26]Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[26]
Storage requirementSealed with desiccant below 20 % RH; shelf life at ambient is long[29][23]Sealed with desiccant; often kept in a dryer during the print[26]
Mechanical Properties
Tensile strength (XY)MPa33 (printed XY, ISO 527); eSun Silk broke 22 % below the 16-brand PLA mean on identical 4×4 mm bars[1][30]Not documented
Young's modulusMPa2130 (printed XY, ISO 527)[1]Not documented
Elongation at break%2.8 (printed XY, ISO 527) — a quarter of PLA Basic at 12.2[1][29]870 at break (Fiberlogy FiberFlex 30D, ISO 527) — the highest elongation in the dataset[2]
Flexural strengthMPa75 (printed XY, ISO 178)[1]Not documented
Flexural modulusMPa2460 (printed XY, ISO 178)[1]Not documented
Charpy impact, notchedkJ/m²10.3 (printed XY, ISO 179, notched); unnotched 18.5[1]Not documented
Layer adhesion / Z tensileMPa25 (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[1][30][31]Not documented
Brittleness1–5Brittle — snaps with little warning[1]Very ductile — bends far before failing[2]
Hardness (scale-specific)Shore A / Shore D / RockwellNot documented81 Shore A and 30 Shore D (Fiberlogy FiberFlex 30D, ISO 7619)[2]
Creep resistance / sustained load1–5Poor — 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]Poor — no creep test at this hardness; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[34]
Fatigue / repeated-flex resistance1–5Poor — no grade-specific S-N curve; plain printed PLA ran 38 000–49 000 cycles at 30 % of tensile strength (R = 0.2)[35][27]Excellent — living hinges viable[22]
Elasticity / flexibility1–5Rigid[1]Rubbery / highly elastic[2]
Z strength as % of XY%76 by tensile, 40 by flexural (printed, Bambu Lab)[1]Not documented
Wear resistance & frictionNot documentedTear strength 95 kN/m (Fiberlogy FiberFlex 30D, ISO 34-1)[2]
Thermal Properties
HDT at 0.45 MPa°C60 (ISO 75, 0.45 MPa)[1]Not documented
HDT at 1.8 MPa°C56 (ISO 75, 1.8 MPa)[1]Not documented
Glass transition (Tg)°C57 (DSC)[1]Not documented
Melting point / Vicat°C158 peak melt (DSC); Vicat 66 °C[1]170 melting (Fiberlogy FiberFlex 30D, DSC)[2]
Continuous service temperature°C50 — a loaded bar begins to move at this temperature (My Tech Fun, eSun eSilk PLA)[31]Not documented
Annealing response50–55 °C for 6–12 h[1]Not documented
Flammability / UL 94Flammable; no UL 94 rating published by the major brands[29][36]Not documented
Environment & Chemical
UV resistance1–5Degrades within weeks outdoors[27][37]Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[22]
Chemical resistanceGood against weak acids, oils and grease; poor against strong acids and alkalis; dissolved by chloroform, THF and hot benzene[36][27]Withstands industrial solvents and UV exposure (Polymaker)[22]
Water / humidity resistance in service1–5Good — insoluble in water[29]Not documented
Food contactBase resin is food-contact grade, but printed layer grooves harbour bacteria; Prusa advises against food use[27]Not food safe without specific certification (Polymaker)[22]
Biodegradability / compostabilityIndustrially compostable only — needs sustained 55 °C; not home compostable[38][27]Not biodegradable[22]
RecyclabilityMechanically recyclable; not accepted in household plastic collection[38]Not accepted in household plastic collection[22]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission[39]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[39]
Ventilation / filtration requirement1–5None needed in a normal room[39]Open a window / occasional ventilation[39]
Post-Processing
Sanding & machiningWet sanding — dry sanding heats the surface by friction and smears it[37][27]Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[22]
Gluing & solvent weldingCyanoacrylate for most joints; some grades partially dissolve and bond with acetone[27][40]Cyanoacrylate bonds TPU; no common solvent welds it[22]
Vapour / chemical smoothingNo practical vapour smoothing — only chloroform, hot benzene or THF, which are laboratory-only[27]No practical vapour smoothing[22]
Support material pairingSupport for PLA (Bambu Lab)[1]Polymaker warns TPU supports are often very difficult to remove[22]
Dimensional accuracy & detail55° overhangs and 30 mm bridges; gloss hides fine detail and is destroyed by sanding[1]Not documented
Solvents & Solubility
Soluble inChloroform: 10 % w/v in 2–4 h at 23 °C, every grade and morphology; THF and DMF only at 65 °C. Laboratory reagents.[41]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[42]
Softened or crazed byAcetone, ethyl acetate and toluene plasticise it but dissolve <1 % even at 65 °C; submersion in acetone crazes and destroys parts.[41][43]Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[42]
Solvent welding & smoothing agentChloroform vapour smooths and welds PLA at the cost of tensile strength; acetone does not smooth it at all.[44][43]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[42]

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 V1.0 — PLA Silk+ Bambu Lab · 2026-08 · tds
  2. FiberFlex 30D Technical Data Sheet Fiberlogy · 2026-08 · tds
  3. Panchroma Silk PLA collection Polymaker Shop · 2026-08 · vendor
  4. Spectrum PLA Silk — product listing 3DJake International · 2026-08 · vendor
  5. 3DJake ecoPLA Silk Black 1.75mm 1000g 3DJake International · 2026-08 · vendor
  6. Recreus product catalogue Recreus · 2026-08 · vendor
  7. Chinchilla product page — print guidelines, spool sizes and price NinjaTek · 2026-08 · vendor
  8. NinjaFlex Edge product page — durometer, print guidelines and price NinjaTek · 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. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  16. eSUN PLA-Silk Magic 1.75mm eSUN Official Store · 2026-08 · vendor
  17. JAYO Silk PLA+ 1.75mm 1.1kg JAYO Official Store · 2026-08 · vendor
  18. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  19. PLA Basic — product page Bambu Lab US Store · 2026-08 · vendor
  20. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  21. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  22. TPU — material basics Polymaker Wiki · 2026-08 · doc
  23. PLA — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  24. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  25. Prusament PLA — material page Prusa Polymers · 2026-08 · doc
  26. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  27. PLA — material guide Prusa Knowledge Base · 2026-08 · doc
  28. Filament Drying Recommendations Bambu Lab 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. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  35. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  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. Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
  42. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  43. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  44. 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