TPU-70A Foam Filament – Ultra-Soft Foam Texture, 1.75mm, 1kg

Shore A measures resistance to indentation — the lower the number, the softer the material. At 70A this is the softest grade we stock: genuinely rubber-like, easy to compress, and best suited to cushioning, gaskets, and squeezable parts. It's also the most demanding to feed, so a direct-drive extruder and slow, steady printing matter more here than on any other grade. TPU Shore hardness explained: 70A vs. 80A vs. 85A vs. 90A vs. 95A walks through which grade fits which project.

Yes — TPU is hygroscopic and picks up moisture faster than most filaments. Dry it as soon as you hear popping or see bubbles, heavy stringing, weak layers, or a rough surface, and print from dry storage whenever you can. How to dry filament at home compares ovens, dry boxes, and dedicated dryers; how to store filament properly covers keeping it dry between prints.

Direct drive is required for this grade. It is too soft to push through a long Bowden tube — the filament coils inside the path instead of advancing. Use a short, constrained route with very low spool resistance. TPU Shore hardness explained covers which grades tolerate which extruder setups.

Moisture is the usual culprit. Dry the filament first — how to dry filament at home covers the options — then lower the nozzle temperature or adjust retraction carefully and keep travel moves efficient. TPU needs a different retraction approach from rigid filaments, which our step-by-step retraction tuning guide covers material by material.

It depends on your printer and feeder. Flexible TPU can buckle or jam in the long feed paths these systems use, so run it from an external spool with a direct feed unless your equipment manufacturer explicitly supports this hardness. Our AMS and multi-material setup walkthrough covers what to check before loading a flexible spool.

Print slowly, calibrate flow, limit acceleration, keep the filament dry, and avoid building excessive pressure at the nozzle. Always test a small calibration part before committing to a production run — what a calibration print tells you explains how to read the result rather than just eyeballing it.

Raise the nozzle temperature gradually and reduce flow to compensate for the foaming expansion. Calibrate with small test samples, because how much it expands changes with temperature, speed, layer height, and hot-end design. TPU Shore hardness explained covers how the Foam finish behaves differently from Glossy and Matte.

Work at the lower end of the nozzle-temperature range and move the flow ratio back toward 100%. Less foaming expansion means a denser, firmer, more dimensionally predictable part. Test on a small sample first — a calibration print will show you the trade-off clearly.