TPU Filament Guide: Shore Hardness, Print Settings, and When to Choose TPU Over PETG
TPU is the most-printed flexible filament for a reason. It stretches, rebounds, shrugs off abrasion, and survives chemicals that would eat PLA for lunch. But two things trip up new TPU users almost every time: buying the wrong Shore hardness for the job, and trying to feed soft TPU through a Bowden tube.
This guide covers the specs that actually matter, the print settings we've seen work reliably, whether an AMS-style multi-material feeder will handle it, and the honest TPU-vs-PETG call for functional parts.
What TPU Filament Actually Is
TPU stands for thermoplastic polyurethane. It's an elastomer, meaning it behaves like rubber at room temperature but softens with heat so it can be extruded like any other filament. Once cooled, it snaps back to its rubbery state.
The properties that make it worth the trouble:
- Elasticity. Stretches and returns without permanent deformation.
- Abrasion resistance. Outlasts ABS and PLA in wear applications by a wide margin.
- Impact strength. Absorbs shock instead of cracking.
- Chemical resistance. Handles oils, greases, and many solvents.
The trade-offs are real. TPU prints slower than rigid filaments, drinks moisture out of the air within a day of opening the bag, and can be genuinely difficult to run through certain extruders. If you skip the drying step, you'll know within the first layer.
Shore Hardness Explained: 85A, 95A, and Which to Buy
Shore hardness is the spec new buyers miss most often, and it's the one that decides whether your part works. TPU is measured on the Shore A scale — lower number means softer and stretchier.
| Shore rating | Feel | Ease of printing | Best use cases |
|---|---|---|---|
| 85A | Very soft, gummy, stretches easily | Hard. Direct drive required, very slow speeds | Watch bands, phone bumpers, squishy grips, soft gaskets |
| 95A | Semi-flexible, tough rubber feel | Moderate. Works on most direct-drive machines | Drone parts, tool handles, wheels, protective cases, vibration mounts |
| 98A / Shore D | Nearly rigid, slight give | Easy. Prints close to PETG behavior | Functional parts needing impact absorption or damping without much flex |
85A is what people mean when they say "soft TPU." It feels like a pencil eraser and stretches like a rubber band. It also compresses in the extruder path, which is why Bowden setups usually can't feed it. If you need something that bends dramatically or grips like rubber, 85A is the answer, but budget the time to dial it in.
95A is the workhorse. If you're not sure what you need, buy 95A. It's flexible enough for drone dampers, tool grips, and protective cases, but rigid enough that most modern printers can feed it at 25–35 mm/s without drama.
98A and Shore D ranges are barely flexible. Think of them as "PETG with a little bounce." Good for parts that need to survive impacts without any real deflection.
TPU Print Settings That Actually Work
Every spool has its own recommended range on the label. Start there. These are the values we reach for when the label is missing or the first attempt fails.
Nozzle and bed temperature
- Nozzle: 220–235°C for typical 95A. Softer TPU often runs cooler (215–225°C), harder TPU a bit hotter.
- Bed: 40–60°C. TPU sticks aggressively to smooth PEI and glass. Higher bed temp isn't better and will make removal harder.
- No enclosure needed. TPU doesn't warp like ABS.
Speed and retraction
- Print speed: 20–40 mm/s. Push it faster and the extruder will skip, giving you under-extruded walls and gaps.
- Retraction: minimize or disable. TPU compresses inside the extruder like a spring. Long retractions push a slug of filament back and forth until it jams. Start with 0.5–1 mm retraction distance, or turn it off entirely and accept a bit of stringing you'll clean up later.
- Direct drive strongly preferred. Bowden setups can push harder TPU (95A and up) with careful tuning, but 85A will buckle inside the tube every time.
Drying TPU before printing
TPU absorbs moisture faster than any other common filament. An opened spool can be too wet to print well within 24 hours in a humid workshop.
Signs your TPU is wet:
- Popping or hissing sounds during printing
- Heavy stringing between features
- Weak layer adhesion (parts delaminate in your hands)
- Dull, matte surface instead of the expected sheen
Dry it at 50°C for 6–8 hours in a filament dryer or a low oven. Print directly from the dryer if you can, and a dry box on the printer will help keep it that way.
Will TPU Run in a Multi-Material Feeder?
Short answer: only harder TPU formulations. High-flow variants like TPU 95A HF (higher hardness, higher flow) can survive most AMS-style multi-material feeders because they resist buckling. Standard 95A and anything softer will not — the flexible material collapses in the tight bends of a multi-material feed path.
For soft TPU (85A) or generic 95A, bypass the feeder entirely. Use the external spool holder that ships with most modern enclosed printers and let the filament run straight into the extruder. Keep speeds conservative regardless of the machine.
If you want to see how our PLA runs through the same class of system, see our AMS-compatible PLA notes.
TPU vs PETG: When to Choose Which
Both are tough. Both handle outdoor use better than PLA. The choice comes down to whether your part needs to flex.
| Property | TPU 95A | PETG |
|---|---|---|
| Flexibility | High (bends and rebounds) | Low (rigid with slight give before cracking) |
| Impact resistance | Very high (absorbs) | Good (resists) |
| Print speed | 20–40 mm/s | 40–60 mm/s |
| Extruder requirement | Direct drive strongly preferred | Any extruder |
| Moisture sensitivity | Very high (dry before every print) | Moderate (dry if stored poorly) |
| Layer adhesion | Excellent (nearly monolithic) | Very good |
| Cost per kg | Higher | Lower |
Choose TPU when the part needs to flex, absorb repeated impact, grip a surface, or bend without cracking. Phone bumpers, drone dampers, gaskets, wheels, wearables.
Choose PETG when the part needs to be rigid but tough. Enclosures, brackets, outdoor mounts, storage bins. PETG is faster to print, works on any extruder, and doesn't punish you for skipping the drying step.
The overlap case: a phone case or tool handle where you want a rigid shell with grippy inserts. A PETG body with printed-in-place TPU inserts often outperforms a full-TPU part. You get the stiffness where you need it and the flex where you want it.
For rigid work, our full PETG guide walks through settings and use cases in the same depth.
What People Actually Print With TPU
The most common projects we see:
- Drones. Camera mounts, antenna guards, prop guards, and vibration dampers. TPU's impact absorption is why racers reach for it after their first crash.
- Phone cases and device bumpers. Repeatable drops without cracking.
- RC wheels and tires. Real grip on real surfaces, printed in an evening.
- Gaskets, seals, and vibration isolators. One-off industrial parts that would cost a fortune to source.
- Wearables. Watch bands, orthotic inserts, custom grip covers.
- Cosplay. Flexible mask sections, articulating joints, foot pads that don't destroy hard floors.
If your project fits any of these shapes, TPU is the right call.
Common TPU Problems and Fixes
Filament grinding in the extruder. The gear is chewing through soft filament instead of pushing it. Reduce retraction distance, drop print speed by 5 mm/s, and check that idler tension isn't cranked too tight. TPU needs enough grip to feed but not so much that it deforms in the gear.
Stringing between features. Almost always wet filament. Dry it first before touching any settings. If strings persist after drying, drop nozzle temperature 5°C at a time until they clear up.
Parts stuck to the bed and won't release. TPU bonds hard to smooth PEI and glass. Drop bed temperature to 40°C, let the bed cool fully before removing, or apply a thin release agent (glue stick or hairspray) as a barrier layer.
Under-extrusion and gaps in walls. Usually a feed problem. If you're on Bowden, that's your first suspect: the filament is compressing in the tube instead of arriving at the hot end. On direct drive, check idler tension and slow down.
A Note on Forgely's Lineup
We should be straight with you: Forgely doesn't currently ship TPU. Our catalog is focused on US-made Performance PLA, 1.75 mm, AMS-compatible, extruded here in Ogden, Utah, wound clean on proprietary spools.
If your workflow is mostly PLA with the occasional TPU project, our PLA is worth a look and we'll happily point you elsewhere for the TPU spool. If you print flexibles as your main workload, shop with a TPU-focused brand today. We track demand signals, and TPU is on the list of possible future additions.
For the PLA side of your bench:
Bottom Line
Three decisions get you a successful TPU part:
- Pick Shore hardness by use case. 85A for gaskets and grippy wearables, 95A for the vast majority of functional parts, 98A when you want damping without real flex.
- Direct drive, slow speeds, dry filament. Skip any one and you'll waste an afternoon.
- If the part doesn't need to flex, use PETG instead. It's easier, faster, cheaper, and it's the right tool when rigidity is the goal.
Buy the hardness that matches the job, dry the spool before you print, and TPU stops being difficult.