TPU vs PETG: Flexible or Tough — Picking the Right Kind of Durable
Updated 2026-06-11 · by Jay
"I want something durable" splits into two different materials depending on what durable means for the part.
The short answer
- TPU when the part must flex, absorb impact, grip, or seal: phone cases, gaskets, RC tires, feet, bumpers, hinges that bend.
- PETG when the part must hold shape under load: brackets, mounts, enclosures, hooks, anything structural.
The deciding question
Should the part give? If bending is a feature, TPU. If bending is a failure, PETG. A TPU bracket sags; a PETG phone case cracks on the third drop. Same word — durable — opposite mechanics.
Printing reality
PETG prints at near-normal speeds on any machine (230-250°C, textured plate, minor stringing). TPU prints slowly — flexible filament buckles when pushed hard, so bowden extruders crawl at 20-30mm/s and even direct drive stays modest. Plan TPU prints by the clock, not the spool.
TPU is also the more moisture-sensitive of the two: wet TPU strings ferociously. Dry it (50-55°C, 6-8h) if it's been out more than a week.
Hardness: the spec that matters for TPU
TPU isn't one material — Shore hardness defines it. 95A is the mainstream choice and what most printers handle well. Softer grades make better gaskets but demand direct-drive hardware; the firm TPU-D grades print easily and land between flexible and rigid.
Cost
TPU typically runs 1.5-2× PETG's price per kilogram — one more reason PETG remains the default for parts that don't actually need to bend. Live prices for both are below and on every filament page.
