Eolas Prints TPU Flex D53 is the softest grade in our flexible filament range — a Shore D53 thermoplastic polyurethane designed for applications where comfort, skin contact, and conformability matter most. It is softer and more pliable than both 93A and D60, making it the right choice for wearables, orthopaedic supports, prosthetics, and any part that needs to flex gently against skin.

Key Properties

Shore hardness	D53 — soft and conformable
Density	1.21 g/cm³
Diameter tolerance	±0.08 mm
Food-contact-safe raw material	Yes — virgin pellets and masterbatches certified to EU food-contact standards (see note below)
Skin contact safe (raw material)	Yes
Toy safe (raw material)	Yes
Extruder compatibility	Direct drive only — not compatible with Bowden systems

A Note on Food Contact

Our food-contact certification applies to the raw filament material — the virgin pellets and masterbatches we manufacture from — not to finished printed parts. 3D-printed surfaces contain microscopic gaps between layers that can harbour bacteria, and most printers use brass nozzles that may introduce trace metals into the print. For this reason, no 3D-printed object can be guaranteed food-safe by the filament alone. If you intend a part for food contact, print it with a stainless-steel nozzle and apply a food-safe sealant — and assess suitability for your specific use. This remains the responsibility of the maker.

Shore Hardness in Context

D53 is significantly softer than our other TPU grades. To put it in perspective: D53 feels like a soft rubber eraser, 93A feels like a car tyre, and D60 feels like a hard rubber sole. Choose D53 when the part needs to flex easily and conform to a surface or body — not when rigidity or wear resistance is the priority.

Extruder Requirements

TPU D53 requires a direct drive extruder. It is not compatible with Bowden systems. At D53 hardness, the filament is too soft to push through a long Bowden tube — it will buckle and jam before reaching the nozzle. Direct drive extruders (Bambu Lab, Prusa MK4, Voron, Ratrig) handle D53 reliably. If you are using a Bowden printer, consider our TPU D60 UV Resistant instead, which is compatible with short Bowden setups.

Bambu Lab AMS is not compatible with TPU — load D53 exclusively via the external spool holder.

Recommended Print Settings

Nozzle temperature	220–230°C
Bed temperature	50–60°C
Print speed	10–20 mm/s
Retraction	0–0.5 mm (minimal retraction)
Cooling fan	50–70%
Extruder	Direct drive only

Drying Before Printing

TPU D53 is highly hygroscopic. Dry at 50–60°C for 4–8 hours if the spool has been open for more than a few days. Wet filament causes stringing, surface bubbles, and weak layer adhesion. Store in a sealed container or dry box with silica gel desiccant between sessions.

Recommended Applications

• Wearables and skin-contact devices — wristbands, sensor mounts, smart textile components
• Prosthetics and orthopaedic supports — socket liners, soft padding components
• Custom grips and handles for tools and sports equipment
• Kitchen accessories — jar grippers, bottle openers (with appropriate food-safe sealing — see note above)
• Gaskets and seals requiring soft, conformable contact
• Flexible prototypes where material compliance is critical

Manufactured in Spain

TPU Flex D53 is manufactured at Eolas Prints' facility in Cantabria, Spain, under ISO 9001 and ISO 14001 standards. Available in 1.75mm and 2.85mm in Black, White, and Grey.