Flexible

What filament should I use for shoes or insoles?

By SSS

Published . Updated .

What is the best flexible filament, and how do I print TPU?

Manufacturer drying table →

Nozzle, Bed, Speed, Drying. Source: Bambu Lab TDS · Last checked 15 October 2026

Ranked filaments

RankFilamentNozzleBedDatasheetBuy
1Bambu Lab · TPU 95A HF
220–240 °C428–464 °F
30–35 °C86–95 °F
Datasheet

Technical data sheet checked 18 October 2026 lists a nozzle of 220–240 °C (428–464 °F), a bed of 30–35 °C (86–95 °F), drying at 70 °C (158 °F) for 8 h, and speed up to 200 mm/s. Shore hardness is not stored on this row. No safety certification is listed.

2Bambu Lab · TPU 85A
200–250 °C392–482 °F
30–35 °C86–95 °F
Datasheet

Nozzle 200–250 °C (392–482 °F), bed 30–35 °C (86–95 °F), drying at 70 °C (158 °F) for 8 h, speed up to 200 mm/s, and Shore 85A stored on the row. No safety certification is listed. 85A is a stiffness figure, not a skin-contact clearance.

3NinjaTek · NinjaFlex TPU
210–240 °C410–464 °F
30–60 °C86–140 °F
—

Open Filament Database, dataset imported 13 October 2026, lists a nozzle of 210–240 °C (410–464 °F) and a bed of 30–60 °C (86–140 °F). Shore hardness, drying, and certifications are empty. The title is not a biocompatibility test.

4Siraya Tech · Flex TPU 64D
240–270 °C464–518 °F
45 °C113 °F
Datasheet

Product TDS page read 23 October 2026 lists a nozzle of 240–270 °C (464–518 °F), a bed of 45 °C (113 °F), and Shore 64D by ISO 7619. It states ISO 10993-5, 10, and 23 tested for biocompatibility support, and it states no contact duration. That is the medical page's row. It is not a shoe approval.

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A shoe touches skin for as long as it is worn. Medical and skin-contact use is the limit. How TPU prints and what Shore hardness means are the material pages. None of them is a footwear clearance, and the comments below do not name a polymer.

Stiffness the rows actually store

Bambu TPU 95A HF lists 220–240 °C (428–464 °F), a bed of 30–35 °C (86–95 °F), drying at 70 °C (158 °F) for 8 h, and speed up to 200 mm/s, sheet checked 18 October 2026. Shore hardness is blank on that row, and and no safety certification is listed. Bambu TPU 85A lists 200–250 °C (392–482 °F), a bed of 30–35 °C (86–95 °F), the same drying cycle, speed up to 200 mm/s, and Shore 85A. No safety certification is listed. NinjaFlex lists 210–240 °C (410–464 °F) and a bed of 30–60 °C (86–140 °F), dataset imported 13 October 2026, with no Shore value and no certification stored.

Siraya Tech Flex TPU 64D lists 240–270 °C (464–518 °F), a 45 °C (113 °F) bed, and Shore 64D by ISO 7619. The TDS page read 23 October 2026 says ISO 10993-5, 10, and 23 were tested for biocompatibility support. It does not state how long contact may last. That row is here because it is the TPU sheet in this catalog that mentions a biocompatibility test. It is not a recommendation to print an insole from it. The customer still has to read the disclaimer on the medical page.

Pros and cons

Pros

  • The page refuses to promote a hobby TPU to a skin-safe insole.
  • The one row that cites an ISO 10993 line is quoted with the limit already on the medical page: no contact duration.

Cons

  • No supplied comments recommends a filament, a shore value, or a print temperature.

Printer considerations

Printer limits

Sources & notes

Published . Updated .

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Related questions

Related data

Questions

Is TPU safe against skin?

Not from these four rows as a group. Bambu TPU 95A HF, Bambu TPU 85A, and NinjaFlex store no certification. Siraya Tech Flex TPU 64D's sheet, read 23 October 2026, says ISO 10993-5, 10, and 23 were tested for biocompatibility support and does not state a contact time. Medical and skin-contact parts is the page that keeps that limit.

Which shore hardness is a shoe?

The comments do not say. The catalog stores Shore 85A on Bambu TPU 85A, with a nozzle of 200–250 °C (392–482 °F) and a bed of 30–35 °C (86–95 °F). Siraya's sheet stores Shore 64D. Shore hardness explains the scale. How to print TPU is the printer setup. Neither page is a footwear standard.