Filament guideMost 3D printed parts are rigid. But phone cases, shoe soles, grips and bumpers need to bend, squish and bounce back. That's what TPU is for. Here's how Bambu Lab's TPU range works, from soft 85A to the firmer TPU for AMS, and how to pick one.
Quick answer
The short answer
TPU (thermoplastic polyurethane) is a flexible, rubber-like filament. It stretches, absorbs impact and resists wear. The number after the name, like 85A or 95A, is its Shore hardness: lower is softer.
Bambu Lab offers TPU 85A (softest), TPU 90A, TPU 95A HF (fast printing) and TPU for AMS, which Bambu rates at Shore 68D, a much firmer scale.
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How Shore hardness works
Shore A measures soft materials. A rubber band sits around the low end, while a shopping cart wheel sits up high. Shore D is a separate scale for harder plastics. So TPU 85A feels squishy, 95A feels like a firm rubber, and 68D is tough with only a little give.
Design matters as much as the material. Bambu notes that more walls and denser infill make TPU prints less elastic. Fewer walls and lighter infill make them softer.
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Bambu's TPU range compared
| Bambu's data | TPU 85A | TPU 90A | TPU 95A HF | TPU for AMS |
|---|---|---|---|---|
| Hardness | 85A | 90A | 95A | 68D |
| Tensile strength | 12.0 MPa | 12.5 MPa | 27.3 MPa | 22.4 MPa |
| Stretch before breaking | >700% | >650% | >650% | >650% |
| Multi-color (AMS) | No | No | No | Yes |
Every version stretches to more than six times its length before breaking. The firmer grades are roughly twice as strong in tension.
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Which TPU for which job
- TPU 85A: the softest. Bambu suggests it for protective cases and fidget toys. It needs a 0.6 or 0.8 mm nozzle.
- TPU 90A: a little firmer. Bambu suggests shoe soles and RC car tires.
- TPU 95A HF: the classic firm-flexible grade. Bambu rates it about three times faster to print than standard TPU 95A, with the same flexibility and impact resistance.
- TPU for AMS: the toughest and least stretchy. It's the one that works with Bambu's multi-color system, so it can be combined with other colors in one print. Bambu suggests phone covers, door stoppers, sports gear and car parts.
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What TPU is good for
- Phone and gadget cases, bumpers and corner guards
- Gaskets, seals, grips and non-slip feet
- Wearables, watch straps and cosplay armor straps
- Shoe soles, insoles and props that need to flex
- Toys and squishy fidgets
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Limits and design tips
- Slow to print. Even the fast grades print slower than PLA, especially soft 85A. That affects turnaround.
- Not food grade. Bambu says not to use TPU for AMS prints for food contact.
- Avoid tiny details and bridges. Soft material sags. Keep features chunky and supports minimal.
- Combine with rigid parts. A rigid shell in PETG with TPU grips or bumpers often works better than an all-flex part.
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TPU at IMPRESO
We print TPU in-house at our Ridgewood, Queens studio. Tell us how soft the piece should feel and what it needs to survive, and we'll recommend the right grade. Every job is quoted individually.
Start a 3D project
Send us your file, a sketch or a reference object with the feel you want. We'll pick the grade and quote it.
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