What TPU hardness numbers mean for your printer
TPU hardness is given on the Shore scale. Bambu Lab’s TPU guide explains that Shore A covers softer grades and Shore D harder ones, and that a higher number means a harder, less flexible filament. It ranks common grades from hardest to softest as 77D, 70D, 68D, 55D, 95A, 90A, 85A, 83A, 80A, 75A and 70A [1].
The softer the filament, the harder it is to push through an extruder. Bambu Lab recommends 85A or harder for stable printing, says softer grades such as 83A or 80A buckle and tangle during feeding, and states that its printers do not currently support TPU rated below 85A [1]. Creality draws its line in a similar place: its K2 Plus filament page says TPU of 80A, 75A, 70A or lower is not recommended on Creality printers because the extruder gear can flatten it and clog the nozzle [3].
Notice that 95A, a widely sold grade, is on the soft side of that list. As the next section shows, none of the multicolour feeders covered here will load 95A for printing; the feeders that accept flexible filament at all do so only for harder grades sold for that purpose.
Multicolour feeders: what each manufacturer allows
This is where most first-time TPU buyers get caught. A combo bundle may advertise TPU support for the printer while the bundled feeder cannot load it. The table summarises what each manufacturer’s own documentation says.
- Bambu Lab’s material table also lists TPU 95A, 85A, 83A and 80A as too soft to pass smoothly through the AMS and AMS lite, which can cause loading and unloading failures and clogs [2].
- Anycubic’s Kobra S1 specification lists TPU among supported filaments with the note that TPU 95A is not compatible with the ACE Pro [6].
| Feeder | Ordinary TPU (95A and softer) | What the manufacturer allows instead |
|---|---|---|
| Bambu Lab AMS, AMS lite, AMS 2 Pro | Not compatible [1] | Bambu’s harder “TPU for AMS” filament works with standard AMS feeding [1] |
| Bambu Lab AMS HT | Only as a sealed dry box; automatic feeding is not used [1] | Feed TPU through the dedicated TPU outlet on the back [1] |
| Creality CFS | Do not feed TPU through it [3] | Print TPU without routing it through the CFS [3] |
| Creality CFS lite | TPU 95A, TPE and softer not supported [4] | Harder flexibles such as TPU 77D and TPU 64D [4] |
| Anycubic ACE Pro | TPU 95A can be dried in the unit but not loaded for printing [5] | Use the printer’s own filament holder for single-colour TPU [5] |
Extruder and nozzle requirements
Look for a direct-drive extruder and avoid long tube paths. Creality’s K1C listing specifies a dual-gear direct drive extruder and includes TPU in its supported filaments [7]. Creality also recommends not printing TPU directly through a PTFE tube because the tube’s resistance affects the result [3]. Bambu Lab lists TPU among supported filaments for the A1 mini [9].
Nozzle choice matters more than many buyers expect. Bambu Lab does not recommend 0.2 mm nozzles or regular high-flow nozzles for TPU, and says 85A TPU cannot be printed with 0.4 mm nozzles [1]. It also advises a new nozzle, or a cold pull on an old one, before switching to TPU, especially if the nozzle previously ran carbon- or glass-fibre filament [1]. Its P1S cold-pull guide gives the reason: flexible TPU may not push out residue left from earlier filament, which can lead to a clog [8].
For H, X and P series printers, Bambu Lab sells a TPU Feed Assist Module that it says reduces feeding resistance and allows feeding through a dedicated TPU inlet [1]. Treat this as an add-on cost if you plan to print TPU often on those machines.
Drying and storage are not optional
Bambu Lab describes TPU as highly hygroscopic. Its guide says humidity degrades TPU print quality, causing bubbles, stringing or poor layer adhesion, and tells owners to dry it thoroughly before printing [1]. Its material table lists drying as required for TPU, with 70 °C for 8 hours in a blast drying oven or 75 °C for 12 hours in an AMS HT, and does not recommend the AMS 2 Pro for TPU drying [2].
After printing, Bambu Lab recommends sealing TPU immediately and storing it with desiccant below 20% relative humidity [1]. This is why its guide recommends printing TPU from an AMS HT or a sealed filament dry box with low feeding resistance, elevated so excess filament is not scraped by the heated bed or nozzle [1].
Worked example: phone case, gasket or grip
Say you want a soft phone case on a Bambu Lab printer with an AMS lite. A 95A spool is within Bambu’s 85A floor for the printer, but the AMS lite is not compatible with it, so you would print from an external spool or dry box as a single-colour job [1]. If you want the case to be part of a multicolour plate, you need a harder grade sold for the feeder, which gives up some softness.
On a Creality printer with a CFS lite, the same logic applies in reverse: 95A is not supported in the CFS lite, but 64D and 77D grades are [4]. On an Anycubic Kobra S1 with ACE Pro, TPU 95A cannot go through the ACE Pro; Anycubic suggests trying the printer’s own filament holder for single-colour printing instead [5][6].
For gaskets and grips, softer is usually what you want, so expect single-colour printing from a dry spool. Bambu Lab also notes TPU is not food-contact grade, so do not plan food-container seals with it [1].
Buyer checklist before you order TPU or a combo
Run through these before paying for a printer, a feeder or a spool of flexible filament.
- Find the hardness floor in your printer maker’s documentation: 85A for Bambu Lab, and 80A or softer is not recommended on Creality printers [1][3].
- Check whether your feeder accepts the exact grade, not just “TPU” [1][4][5].
- Confirm a direct-drive extruder and a short, low-resistance filament path [3][7].
- Check the nozzle size against the grade; 85A will not print through a 0.4 mm nozzle on Bambu Lab printers [1].
- Budget for a sealed dry box or drying time on every spool [1][2].
- Plan a cold pull when switching from other filaments to TPU [8].
- Skip a multicolour combo if TPU parts are your main reason for buying; the feeder adds cost without helping soft TPU.
Questions before you decide
Can I print TPU through a Bambu Lab AMS?
Not ordinary TPU. Bambu Lab says the AMS, AMS lite and AMS 2 Pro are not compatible with TPU, the AMS HT can only act as a sealed dry box fed through its TPU outlet, and its harder TPU for AMS filament is the exception that works with standard feeding.
Does the Creality CFS support TPU?
Creality says not to feed TPU through the CFS because it tends to bend in the CFS tube and cause extrusion and retraction failures. The CFS lite supports harder flexibles such as TPU 77D and 64D but not TPU 95A or softer.
Can the Anycubic ACE Pro print TPU 95A?
Anycubic says the ACE Pro can dry TPU 95A but cannot load it for printing; it suggests using the printer’s filament holder for single-colour printing.
What is the softest TPU I can use?
Bambu Lab printers do not support TPU below 85A. Creality does not recommend 80A, 75A, 70A or softer on its printers. Check your own model’s documentation before buying softer grades.
Sources & verification
Product details and prices can change. Check the linked provider before buying.
- Bambu Lab Wiki: TPU printing guide Accessed 30 Oct 2026
- Bambu Lab Wiki: filament guide and material table Accessed 30 Oct 2026
- Creality Wiki: K2 Plus filament parameters Accessed 30 Oct 2026
- Creality Wiki: CFS lite filament compatibility guide Accessed 30 Oct 2026
- Anycubic Wiki: Notes for ACE Pro Accessed 30 Oct 2026
- Anycubic Australia: Kobra S1 product page and specifications Accessed 30 Oct 2026
- Creality: K1C product page and specifications Accessed 30 Oct 2026
- Bambu Lab Wiki: P1S cold pull Accessed 30 Oct 2026
- Bambu Lab US store: A1 mini specifications Accessed 30 Oct 2026
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