TPU Filaments That Earn Their Keep — 6 for 2026
Pick the right flexible filament for drop-resistant phone cases without jamming your hotend.
Sliced · Operator: Emery Castellanos · Links rechecked Nov 14, 2026
; fundingAs an Amazon Associate, Omnexo Store earns from qualifying purchases. A purchase through an Amazon link here can send the site a commission while your price stays the same — and no brand buys a slot in a guide. Funding details
Makers printing phone cases and drop guards keep running into hotend jams and stringy retraction failures. Print logs show endless disagreement on whether direct-drive extruders are mandatory or if a tuned Bowden setup can handle softer blends. When preparing your machine, remember that drying wet filament is often the key to avoiding interlayer bubbles. This lineup covers a range of hardness ratings, from the rubbery 85A options by Siraya Tech and iSANMATE to the stiffer 95A rolls from SainSmart and TINMORRY. You will also find specialized choices like the low-density SainSmart Air and a flexible 92A pro variant designed to bridge the gap between rigid plastic and pure rubber.
Bench method → I compared manufacturer listings, spec sheets, and printer compatibility notes, then cross-checked public buyer feedback to drop duplicates. Editorial policy
Dial This In Before You Order
Hardness ratings dictate every mechanical property of a flexible print. A Shore 85A material yields a genuinely rubbery case that absorbs shock well, but it demands slow print speeds and a direct-drive extruder to prevent buckling inside the heat break. Shore 95A rolls like TINMORRY's 1kg spool offer higher stiffness, making them far easier to push through standard extruders while keeping enough give for snap-fit designs.
Diameter tolerance is another critical spec to compare on the sheet. Look for a plus-or-minus 0.05 mm variance to avoid uneven extrusion widths that ruin tight tolerances around phone buttons and camera cutouts. Pay close attention to spool compatibility notes as well; some soft filaments refuse to feed through closed automatic material systems.
Storage matters immensely for hygroscopic elastomers. Siraya Tech ships its flex material in a moisture-resistant aluminum bag with a 3-year shelf life, sparing you immediate drying cycles. A common mistake is buying a soft 85A spool for a printer running a long Bowden tube without upgrading to a direct-drive toolhead first.
On the Build Plate
Siraya Tech Flex TPU 85A 1kg
by High Flexibility &
The listing omits exact spool mass and hotend temperature ranges, but the spec sheet confirms a 1.75 mm diameter and an 85A hardness rating tailored for high-flow extrusion. Siraya Tech packages this material inside a moisture-resistant aluminum bag rated for a 3-year shelf life. A direct drive setup handles the high-flow output better than a Bowden setup, and you should skip this roll if your machine lacks direct drive feeding. ISO 10993 testing covers biological responses for external wearables, which matters when you print a tight-fitting phone case that spends hours against your hand.
; print notes
; Prints well
Prints well: features ISO 10993 biological testing
Prints well: rated for high-flow extrusion
Prints well: sealed in aluminum packaging
iSANMATE TPU 85A Flexible Filament 1kg
Designed with a soft 85A shore hardness, this iSANMATE flexible filament brings a rubbery texture to protective phone cases and impact bumpers. The spool contains a 1.75 mm diameter filament engineered to maintain a reliable flow rate across compatible extruders.
Next layer:Shortlisted for the Print Farm: 5 Resin Wash and Cure Stations
SainSmart Matte TPU Filament 95A 1kg
Offering a balanced 95A shore hardness, this SainSmart matte TPU filament provides the structural rigidity needed for snug phone cases while retaining light impact absorption. The material is packaged on a standard 1 kg spool with a consistent 1.75 mm diameter for smooth extrusion.
TINMORRY TPU 95A Flexible Filament 1kg
by 95A Shore Hardness,
Stiff enough for snap-fit phone cases yet retaining rubbery give, this TINMORRY TPU 95A filament relies on a 1.75 mm diameter with a plus-or-minus 0.05 mm tolerance. Anyone feeding material into a multi-material unit should note that the spool is explicitly incompatible with Bambu AMS setups. You will need to manage moisture carefully since the material demands a drying routine of 70 degrees Celsius for 8 hours in an oven. The nozzle range spans 210 to 240 degrees Celsius alongside a bed temperature of 30 to 50 degrees Celsius.
; print notes
; Prints well
Prints well: Shore hardness of 95A
Prints well: Cardboard or plastic spools
Prints well: Compatible with Bambu FDM
; Watch for
Watch for: Not compatible with Bambu AMS
Watch for: Requires high drying temperatures
Next layer:5 3D Printer Enclosures for Beating Enclosure Heat
SainSmart Flex TPU Air Lightweight 1kg
Crafted as a specialized lightweight formula, this SainSmart Air TPU filament reduces overall phone case weight without sacrificing drop protection. The spool features a 1.75 mm diameter spool designed to print with reduced density on direct-drive setups.
Next layer:What Separates a Good Scanning Objects For Printing From a Bad One (9 Picks)
Flexible PLA Filament 92A Pro 1kg
by 1.75mm 1KG, Soft
Bridging the gap between rigid polyesters and soft elastomers, this 92A pro flexible filament delivers a smooth finish for custom phone cases. The 1 kg spool features a 1.75 mm diameter engineered to minimize stringing during retraction.
Troubleshooting Q&A
Can I print flexible filament using a standard Bowden extruder?
It depends. Softer 85A materials like the iSANMATE roll tend to buckle inside long PTFE tubes, while stiffer 95A options manage the journey much better if you dial down retraction speeds.
Why won't my multi-material unit accept the TINMORRY TPU spool?
The spool is explicitly incompatible with closed multi-material feeder units like the Bambu AMS, meaning you must feed it externally.
How do I keep TPU filament from absorbing moisture?
Store opened spools in a dry box or a sealed container with desiccant, though options like Siraya Tech arrive protected inside an aluminum bag.
What is the difference between 85A and 95A hardness ratings?
An 85A Shore rating gives you a noticeably softer, more rubbery feel ideal for impact absorption, whereas 95A is stiffer and suits snap-fit geometries.
Do I need a hardened steel nozzle for flexible filaments?
Standard brass nozzles work fine unless you choose a filled composite variant.
What print speed should I set for flexible phone cases?
Keep speeds slow to prevent the soft filament from slipping or jamming in the drive gear.
Are all these spools 1kg in weight?
Yes.
Found a dead link or a spec that changed? Send a correction and it gets fixed.
Operator log
Emery Castellanos— Print-bench researcher · FDM printers, filament & upgrade parts
I compare 3D printers, filament and upgrade parts by spec sheet, firmware notes and printer compatibility, so the spool or hotend you order fits the machine on your bench. No brand sends me anything.