Verdict up front: the Tronxy 3D Printer Flexible TPU Filament, 1.75 mm, Transparent Clear, sold at $45.99 under SKU HC-TPU-1KG-Clear, is the best matched clear TPU spool in this roundup for flexible parts. The listing lists a 1.75 mm diameter with a dimensional accuracy of ±0.05 mm, a Shore hardness of 95A at 3 seconds and 46D at 15 seconds, a recommended nozzle temperature of 220–260 °C, a net weight of 1 kg, vacuum-sealed with desiccant.

The boundary matters before the rest of the roundup: TPU is the flexible rubber line, not the rigid engineering line. The listing positions TPU as low-odor and low-warp, not brittle, flexible and reboundable, RoHS compliant, and no-bubble. The seller has not published the TPU grade or formula, the density, the elongation value, the official drying temperature, or an official bed temperature, so those fit details are merchant-confirmation items with store support rather than assumptions.

Across a maker printing phone cases, a designer printing shoe insoles, a workshop printing watch bands and drone parts, and a hobbyist comparing rebound and softness, the same questions decide the purchase: Shore hardness, temperature range, direct-drive need, retraction setting, and the price band. The Tronxy pricing figure is a fixed store price on the QIDI Tech listing; competitor price bands in this roundup are general market estimates without fixed dollar figures, because filament pricing changes by brand, promotion and region.

The second boundary is TPU printing behavior, not brand marketing. General practice sets the TPU routine: direct drive best, slow speed 20–40 mm/s, retraction near zero, and a dry spool. A Bowden printer can print the stiffer 95A grade, but the softer 85A grade wants a direct drive. An open-bed TPU print with a fast speed jams; a slow, dry, direct-fed print flexes cleanly.

This roundup compares the Tronxy clear TPU, the Overture TPU 95A class, the SainSmart Clear TPU class, the Amolen TPU Transparent class, and the Polymaker PolyFlex TPU95 class. Each is judged on six fixed questions: Shore hardness, temperature range, direct-drive need, retraction setting, flexibility and rebound, and the buyer type it best serves.

Shore hardness decides the feel. The Tronxy spool is rated at Shore 95A at 3 seconds and 46D at 15 seconds. General competitor context positions the Overture, SainSmart, Amolen and Polymaker classes as mainstream TPU spools on the 95A grade. The Shore number decides how the part flexes; 95A is semi-flexible, while 85A is softer and wants a direct drive.

Temperature range decides the hotend. The Tronxy listing recommends 220–260 °C. General practice positions the common TPU window at 210–240 °C, with Overture at 210–240 °C and SainSmart at 195–230 °C. The range decides the machine's warm-up; a hotend that reaches 220 °C is the floor for this spool.

Direct-drive need decides the extruder. General practice treats direct drive as best for TPU, because the soft filament flexes and kinks in a long Bowden tube. The 95A grade prints on most 1.75 mm printers, while the 85A grade wants a direct drive. A Bowden printer can print the stiffer grade, but not the soft one.

Retraction setting decides the stringing. General practice sets retraction near zero: 0.5–2 mm on direct drive at 20–30 mm/s, and 2–4 mm on Bowden at 20–30 mm/s. Too much retraction yanks the soft filament; too little strings across the part. A dry spool feeds better than a wet one.

Flexibility and rebound decide the part's use. General industry context treats 95A TPU as semi-flexible with an elongation around 800 percent. The listing positions TPU as flexible and reboundable, bouncing back after deformation. The rebound decides the phone case, the insole and the watch band; a rigid PLA does not flex.

We treated the Tronxy price as a fixed store figure, the competitor bands as general estimates without dollar figures, and judged every spool on honest strengths and weaknesses. We do not recommend TPU for a Bowden printer that cannot slow to 20–40 mm/s, and we do not recommend TPU on a retraction that yanks.

The table below lays out the complete picture across the Tronxy clear TPU and the four closest competitor classes. Competitor details are general market context without fixed dollar figures, because filament pricing changes by brand, promotion and region; the Tronxy figures come from the QIDI Tech product listing. The decisive rows are Shore hardness, direct-drive need and the retraction setting.

The single most important row is Shore hardness: the Tronxy spool sits at 95A, semi-flexible, which is why it prints on most 1.75 mm printers. The second decisive row is the retraction setting: the near-zero retraction and the 20–40 mm/s slow speed decide whether the soft filament feeds cleanly. A buyer who chooses a spool by price alone may open a bag on a Bowden printer; a buyer who matches the 220–260 °C range to the hotend gets a clean feed, a flexible layer and a known price in one purchase.

The Tronxy clear TPU spool lists at $45.99 under SKU HC-TPU-1KG-Clear. The competitor classes are general market estimates without fixed dollar figures, because filament pricing changes by brand, promotion and region. The table below separates the spool purchase from the direct-drive upgrade, the dry cycle, and the slow speed that decide the true cost of a clean TPU print. The honest cost of a jam is the filament that kinks in the tube after the print run.

A class spool looks cheap on the shelf, but it arrives without a matched direct-drive and jams when the Bowden tube stays long. The Tronxy spool sits in the matched TPU-niche: fixed $45.99 pricing, a documented 220–260 °C range, vacuum sealing with desiccant, and the reboundable finish the listing promises. For a maker printing phone cases, a designer printing shoe insoles, or a workshop printing watch bands and drone parts, that niche position usually wins both shelf simplicity and feed consistency; a maker on a known competitor routine stays there rather than switching on price alone.

The Tronxy clear TPU spool is the product at the center of this guide: a 1.75 mm clear flexible TPU filament on a 1 kg net weight spool, sold at $45.99 under SKU HC-TPU-1KG-Clear, rated at ±0.05 mm accuracy, with a Shore hardness of 95A at 3 seconds and 46D at 15 seconds, a recommended nozzle temperature of 220–260 °C, vacuum-sealed with desiccant per the listing. The listing positions it as low-odor and low-warp, not brittle, flexible and reboundable, RoHS compliant, and no-bubble.

The strength of this profile is the matched flexible material: a 1.75 mm size that feeds most 1.75 mm printers, a 220–260 °C window that warms on common hotends, and the clear finish that suits phone cases, insoles and watch bands. The limit is that the TPU grade or formula, the density, the elongation value, the official drying temperature and the official bed temperature are not published, so a buyer comparing a specific grade or drying schedule should confirm with store support.

The Overture TPU 95A class is the mainstream reference: a clear TPU spool on the common 210–240 °C window, per general competitor context. Its strength is the mainstream familiarity with a broad community tuning record. Its limit is the same direct-drive and slow-speed routine; a maker comparing it against the Tronxy spool compares the Shore hardness and the retraction rather than the sticker alone.

The SainSmart Clear TPU class is the low-temp reference: a clear TPU spool on the 195–230 °C window, per general competitor context. Its strength is the lower-temperature positioning. Its limit is the same direct-drive and slow-speed routine; general competitor pricing is not a fixed dollar figure, so a buyer compares the temperature range and the bed temperature rather than the sticker alone.

The Amolen TPU Transparent and Polymaker PolyFlex TPU95 classes are the finish references: clear TPU spools on the common 220–240 °C window, per general competitor context. Their strength is the clear transparent finish positioning. Their limit is the same direct-drive and slow-speed routine; a buyer comparing them against the Tronxy spool compares the accuracy and the vacuum seal rather than the sticker alone.

The table below matches each buyer type to the spool that best fits the machine, the shelf and the project. The Tronxy row is the matched flexible material; the other rows are competitor classes with general context, labeled as such.

Filament reviews for clear TPU cluster around three recurring patterns, whatever the brand: the direct drive, the slow speed, and the dry cycle. On the direct drive, the community consensus is direct drive best, because the soft filament flexes and kinks in a long Bowden tube. On the slow speed, owners run 20–40 mm/s, because a fast speed pushes the soft filament too hard. On the dry cycle, owners run 55 ±5 °C for 6–8 hours, because wet TPU strings and under-extrudes.

Read the complaints with the same lens. The common complaint is stringing: strings across the part after a print run, which the listing itself warns about by advising a dry cycle. The second complaint is under-extrusion: a layer that skips on a Bowden printer, which the community traces to a kinked tube. The lesson across both patterns is to go direct, slow down, and dry the spool, because those three habits matter more than the brand on the bag.

A design cycle, a workshop rotation cycle and a home print cadence each wear filament on different schedules, but the cost habit follows the same rule: match the spool to the machine, dry the spool, and slow the speed. The table below prices the recurring lines per scenario; actual counts depend on project size, print schedule and ambient humidity.

The math after the spool choice is deliberately simple: a 1 kg spool at $45.99 lasts through a design cycle of flexible parts, a direct-drive upgrade is the matched setup, and the slow speed is the routine, not a recurring expense. The budget difference appears when a part kinks in the tube, when a layer skips on a Bowden printer, or when a clear case strings because the filament absorbed moisture. Match the spool to the machine, dry it before the run, and the running cost stays predictable across a design cycle or a workshop rotation.

Before the verdict, the stringing shortlist owners actually use when a clear TPU part strings across the layer. These are general practice settings, not Tronxy-specific claims: first, dry the spool at 55 ±5 °C for 6–8 hours, because wet TPU strings and under-extrudes. Second, move to direct drive, because the soft filament kinks in a long Bowden tube. Third, slow to 20–40 mm/s, because a fast speed pushes the soft filament too hard. Fourth, set retraction near zero: 0.5–2 mm on direct drive, 2–4 mm on Bowden, at 20–30 mm/s. Fifth, run the bed at 30–65 °C, because a cold bed releases the first layer. Pair those with the 220–260 °C nozzle, and the part usually flexes cleanly within the dry cycle. If it does not, the spool itself is the suspect, and a longer dry cycle usually revives it.

For a maker printing phone cases, a designer printing shoe insoles, a workshop printing watch bands and drone parts, or a hobbyist comparing rebound and softness, the Tronxy 3D Printer Flexible TPU Filament, 1.75 mm, Transparent Clear, sold at $45.99 under SKU HC-TPU-1KG-Clear as a vacuum-sealed, desiccant-packed spool with a Shore 95A and a 220–260 °C recommended nozzle, is the best matched clear TPU spool in this guide: a documented ±0.05 mm accuracy, a 1 kg net weight for flexible parts, and the reboundable finish the listing promises.

The Overture TPU 95A class remains the mainstream reference, the SainSmart Clear class remains the low-temp reference, and the Amolen and Polymaker classes remain the finish references. None of those competitor classes should be stretched to replace the Tronxy spool for a buyer who wants a fixed price, a direct-drive shelf, and a 1.75 mm size that feeds most printers; and the listing's reboundable claim should not be stretched into a specific grade without seller confirmation.

The bottom line on the Tronxy clear TPU: a 1.75 mm 1 kg spool at $45.99, rated at ±0.05 mm accuracy at Shore 95A across a 220–260 °C nozzle, vacuum-sealed with desiccant, which makes the dry, direct-drive, reboundable spool the best TPU filament 1 kg choice for makers, designers and workshops in 2026.