3D Printing Info

Filament comparison

PLA Stone vs TPU 85A

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

Stone-filled PLA guideTPU 85A guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PLA Stone comparisonsMore TPU 85A comparisons
PLA Stone vs TPU 85A — documented properties and sources
PropertyStone-filled PLAPLATPU 85AFLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$22.99/kg median; $15.99–$49.16/kg across 6 dated product listings$89.89/kg median; $31.99–$106.05/kg across 6 dated product listings
Identity & Market
Base polymer / chemistryPLA filled with stone or mineral powder — Formfutura StoneFil declares 40–50 wt% stone powder[1][2]Soft thermoplastic polyurethane at 82–85 Shore A[3][4][5]
Densityg/cm³1.22 (Bambu Lab PLA Marble) and 1.50–1.70 (Formfutura StoneFil), ISO 1183[2][1]1.11 (BASF Ultrafuse 85A) to 1.19 (NinjaFlex 85A), ISO 1183 / ASTM D792[5][3]
Typical priceUSD/kg1 kg spools cluster near 21[6][7]1 kg-equivalent spools span 32–106; the middle of the market is about 90[8][9][3]
Price range across brandsUSD/kg16–49 across brands; SUNLU 16, ELEGOO 19, Polymaker 21, Bambu Lab 25, Prusament 38, Filament PM MarbleJet 49 on 0.5 kg spools[10][7][6][11][12][13]32–106 across brands; Siraya Tech Flex TPU 85A 32 at 1 kg, add:north TPU Pro Matte 85A 72, Recreus Filaflex 82A 90 at 500 g, Proto-pasta Clear Flexible TPU 90, 3DXTech 3DXFLEX 85A 96, NinjaTek NinjaFlex 106[14][8][9][15][3]
Market availability1–5Stocked by most mainstream brands[6][7][10]Available from several mainstream brands[8][14]
Spool sizes & diameters1.75 and 2.85 mm; 0.5 and 1 kg spools plus refills[7][1]1.75, 2.85 and 3 mm; 0.5, 1 and 2 kg spools[8][14][3]
Typical applicationsArchitectural models, sculpture and props with a matte mineral surface[2]Soft-touch grips, seals, wearables and anything that must compress and rebound[3][4]
Printing Parameters
Nozzle temperature°C190–230 (Bambu Lab)[2]200–220 (BASF Ultrafuse 85A, 210 typical)[5]
Bed temperature°C35–45 (Bambu Lab)[2]40 (BASF Ultrafuse 85A)[5]
Enclosure / chamber requirement1–5Open frame is fine[2]Open frame is fine[5]
Part cooling fanFan on[2]Not documented
Bed surface & adhesion aidNot documentedPEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[16][17]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sNot documented1.2–3.2 at the 15–40 mm/s BASF specifies on a 0.4 mm nozzle at 0.2 mm layer[5]
Warping tendency1–5Not documentedNone[5]
Bed-adhesion difficulty1–5Not documentedSticks to anything — Recreus states its 82A grade has excellent bed adhesion without a heated bed or additives[4]
Stringing / oozing tendency1–5Not documentedHigh — drying plus tuning needed[18][17]
Overall printing difficulty1–5Easy — minor profile tuning; 0.2 mm nozzles are not usable[19]Advanced — enclosure, hardware upgrades, tuning; at this hardness the filament will not push through a Bowden tube[3][4]
Extruder requirementNozzles below 0.4 mm are not compatible (Bambu Lab)[19]Direct drive only. NinjaTek calls its 85A grade ideal for direct-drive extruders and Recreus specifies direct-drive printers for 82A; BASF caps print speed at 15–40 mm/s with a nozzle of 0.4 mm or larger[3][4][5]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass acceptable; hardened steel for volume work — Bambu Lab's compatibility table says no hardened nozzle is needed while the note under the same table groups PLA Marble with particle-filled materials that should always use one[19]Brass fine indefinitely[20]
Abrasiveness1–5Moderately abrasive — stone fill[19][1]Non-abrasive[20]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle[19]High — jams from moisture, heat creep or particles[18][17]
Heat-creep / jam sensitivity1–5Not documentedVery high — softens in the cold zone readily; soft filament buckles between the drive gear and the melt zone[17][3]
Hotend requirementNot documentedNo special hot-end required, but a direct-drive extruder is (Simplify3D)[16]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate — 0.44 % saturated at 25 °C / 55 % RH[2]Moderate — NinjaTek measures 0.22 % in 24 h (ASTM D570) and BASF specifies a 70 °C dry for at least 5 h[3][5]
Equilibrium moisture content at ~50 % RH%0.44 saturated at 25 °C / 55 % RH (Bambu Lab)[2]0.22 after 24 h water immersion (NinjaFlex 85A, ASTM D570) — an immersion figure, not an equilibrium moisture content at 50 % RH[3]
Drying temperature & timeNot documented70 °C for at least 5 h in a hot-air dryer or vacuum oven (BASF)[5]
Symptoms when wetNot documentedBubbling and popping at the nozzle, stringing and a rough surface[18]
Effect of moisture on strengthPolymaker rates PLA low-sensitivity and publishes no dry-versus-conditioned figures for this grade; absorbed water flashes to steam and shows as bubbling and poor layer adhesion[18]Polymaker groups TPU with the highly hygroscopic materials; wet TPU prints with poor layer adhesion and weak, brittle layers[18]
Storage requirementNot documentedSealed with desiccant; often kept in a dryer during the print[18]
Mechanical Properties
Tensile strength (XY)MPa33 ± 4 printed XY, ISO 527 (Bambu Lab)[2]26 ultimate (NinjaFlex 85A, ASTM D638)[3]
Young's modulusMPa2330 ± 240 printed XY, ISO 527 (Bambu Lab)[2]12 (NinjaFlex 85A, ASTM D638) — two orders of magnitude below any rigid filament; NinjaTek's 95A Cheetah reaches 26 by the same method[3][21]
Elongation at break%6.7 ± 0.5 printed XY, ISO 527 (Bambu Lab)[2]650 at break (Filaflex 82A) and 660 (NinjaFlex 85A); BASF measures 600 in XY and 320 in ZX[4][3][5]
Flexural strengthMPa75 ± 5 printed XY, ISO 178 (Bambu Lab)[2]Not documented
Flexural modulusMPa2920 ± 180 printed XY, ISO 178 (Bambu Lab)[2]Not documented
Charpy impact, notchedkJ/m²9.5 ± 2.6 printed XY, ISO 179, notched (Bambu Lab)[2]Not documented
Other impact dataCharpy unnotched 24.0 printed XY (Bambu Lab, ISO 179)[2]Not documented
Layer adhesion / Z tensileMPa30 ± 4 printed Z, ISO 527 (Bambu Lab)[2]Not documented
Brittleness1–5Brittle — snaps with little warning[2]Very ductile — bends far before failing[3]
Hardness (scale-specific)Shore A / Shore D / RockwellNot documented29 Shore D / 85 Shore A (BASF Ultrafuse 85A, ISO 7619-1); 85 Shore A (NinjaFlex, ASTM D2240); 82 A nominal for Filaflex[3][5][4]
Creep resistance / sustained load1–5Poor — no stone-filled creep test; plain printed PLA sagged from 12 to 16.2–21.8 mm over 5 days at 1.25 kg[22][23][24]Poor — no 85A creep test; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg, and softer grades creep more[25]
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 and the mineral filler leaves a brittle compound[26][2]Excellent — living hinges viable[17]
Elasticity / flexibility1–5Rigid[2]Rubbery / highly elastic[3][4]
Z strength as % of XY%91 by tensile, 73 by flexural (printed, Bambu Lab)[2]53 — BASF measures 320 % elongation at break in ZX against 600 % in XY[5]
Wear resistance & frictionNot documentedAbrasion 0.08 g mass loss over 10 000 cycles (NinjaFlex, ASTM D4060); 82 mm³ (BASF, ISO 4649)[3][5]
Thermal Properties
HDT at 0.45 MPa°C56 (ISO 75, 0.45 MPa)[2]Not documented
HDT at 1.8 MPa°C53 (ISO 75, 1.8 MPa)[2]Not documented
Glass transition (Tg)°C56 (DSC)[2]Not documented
Melting point / Vicat°C156 peak melt (DSC); Formfutura gives a 120–170 melting range for StoneFil[2][1]216 melting (NinjaFlex 85A, DSC)[3]
Environment & Chemical
UV resistance1–5Degrades within weeks outdoors[27]Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[17]
Chemical resistanceNot documentedWithstands industrial solvents and UV exposure (Polymaker)[17]
Food contactNot documentedNot food safe without specific certification (Polymaker)[17]
Biodegradability / compostabilityNot documentedNot biodegradable[17]
RecyclabilityNot documentedNot accepted in household plastic collection[17]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission[28]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[28]
Ventilation / filtration requirement1–5None needed in a normal room[28]Open a window / occasional ventilation[28]
Dust & fibre handling hazardFormfutura's SDS sets an occupational limit of 1 mg/m³ for the stone powder and lists it as both a fibre and a particulate — do not dry-sand without extraction[1]Not documented
Post-Processing
Sanding & machiningSands to a stone-like matte surface[1]Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[17]
Gluing & solvent weldingNot documentedCyanoacrylate bonds TPU; no common solvent welds it[17]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing[17]
Support material pairingSupport for PLA (Bambu Lab)[2]Polymaker warns TPU supports are often very difficult to remove[17]
Dimensional accuracy & detailMatte mineral surface hides layer lines; 55° overhangs and 30 mm bridges as for plain PLA[2]Not documented
Solvents & Solubility
Soluble inChloroform dissolves the PLA matrix (10 % w/v, 2–4 h at 23 °C) and leaves the filler as loose sludge; laboratory reagent.[29]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[30]
Softened or crazed byAcetone, ethyl acetate and toluene plasticise the matrix but dissolve <1 % even at 65 °C; acetone submersion crazes parts.[29][31]Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[30]
Solvent welding & smoothing agentChloroform vapour attacks only the resin fraction, so the filler is left standing proud; no workshop-safe agent exists.[32][31]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[30]

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. StoneFil safety data sheet Formfutura · 2026-08 · msds
  2. Bambu Filament Technical Data Sheet — PLA Marble Bambu Lab · 2026-08 · tds
  3. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  4. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  5. Ultrafuse TPU 85A Technical Data Sheet (Version 3.0) BASF Forward AM · 2022-08 · tds
  6. PLA Marble — product page Bambu Lab US Store · 2026-08 · vendor
  7. Polymaker product catalogue Polymaker · 2026-08 · vendor
  8. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  9. Siraya Tech Flex TPU 85A Filament — product page Siraya Tech · 2026-08 · vendor
  10. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  11. Printed Solid product catalogue Printed Solid · 2026-08 · vendor
  12. SUNLU High Speed PLA Marble 3D Printer Filament 1 kg SUNLU · 2026-08 · vendor
  13. Filament PM PLA MarbleJet technical data sheet Filament PM (Plasty Mladec) · 2026-08 · tds
  14. Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
  15. add:north TPU Pro Matte 85A product page add:north · 2026-08 · vendor
  16. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  17. TPU — material basics Polymaker Wiki · 2026-08 · doc
  18. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  19. PLA Usage Guide Bambu Lab Wiki · 2026-08 · doc
  20. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  21. NinjaTek technical specs comparison chart (Cheetah, NinjaFlex, Armadillo, Alloy 910, Nylon 645) NinjaTek · 2026-08 · tds
  22. BambuLab PLA Basic vs PLA Tough vs PLA-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  23. Polymaker PLA Pro vs PLA-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  24. Carbon Fiber PLA vs META-PLA vs PLA+ vs PLA by Sunlu — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  25. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  26. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  27. PLA — material guide Prusa Knowledge Base · 2026-08 · doc
  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. Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
  30. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  31. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  32. 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