How to print with flexible filament (2026)
Quick Answer
To print with flexible filament, use a dry spool, a clear and well-constrained filament path, and slower, steadier print settings than you would for rigid plastics. Start with the filament maker’s recommended nozzle and bed settings, reduce print speed and retraction, and make sure the first layer is well bonded before running a full print.
Overview
Flexible filaments such as TPU and similar elastomer-based materials behave very differently from PLA or PETG. They bend, compress and grip inside the extruder path, which makes them more likely to buckle, jam or feed inconsistently if the printer is not set up carefully. The good news is that many modern FDM printers can handle flexible materials well if you prepare properly. The key to success is control. Flexible filament prints best when the filament path from drive gear to hot end is as short and supported as possible, the filament is dry, and the printer is not trying to push it too fast. You should also expect to fine-tune slicer settings such as speed, retraction and cooling based on the exact filament and your printer’s extruder design. A direct-drive extruder is usually easier to use than a long Bowden setup, but either can work if the path is constrained and settings are conservative. This guide focuses on practical setup, loading, slicer choices and test-printing so you can get reliable results without wasting material. For exact temperatures, drying advice and speed limits, always use the filament manufacturer’s data sheet and your printer maker’s guidance, because these vary by material formulation and machine design.
Who this is for
Home users, hobbyists, school workshop users and small makers using FDM/FFF 3D printers who want to print TPU or similar flexible filaments more reliably.
What you’ll need
- 3D printer in good working order
- Flexible filament such as TPU or another manufacturer-supported flexible material
- Slicer software for your printer
- Printer and filament manufacturer guidance for recommended settings
- Clean print surface suitable for your printer
- Access to the extruder path so you can inspect and guide filament loading
- Dry storage or drying method recommended by the filament manufacturer
Before you start
Check whether your printer is suitable for flexible filament, especially the extruder design and how well the filament is supported between the drive gear and hot end. Confirm the filament is dry, the nozzle is not partly clogged, the bed is level or correctly probed, and the filament maker provides settings for nozzle temperature, bed temperature, print speed and drying. If your printer maker has a flexible-filament profile, start with that rather than a generic preset.
Step-by-step
- 1
Confirm printer compatibility and inspect the filament path
Look at the route the filament takes from the drive gear into the hot end. Make sure there are no large gaps where soft filament can kink or buckle. If your printer has interchangeable extruder parts or a manufacturer-recommended flexible-filament path, fit those before printing.
Why: Flexible filament compresses and bends under feed pressure. A well-supported path reduces the chance of the filament folding inside the extruder instead of moving cleanly into the hot end.
- 2
Dry and store the filament properly
Use the filament only after drying it according to the filament manufacturer’s instructions, and keep the spool sealed or in dry storage when not in use. If the spool has been left out, assume it may need drying again before an important print.
Why: Flexible materials can absorb moisture from the air. Damp filament often causes popping, stringing, rough surfaces and inconsistent extrusion.
- 3
Prepare the printer and build surface
Clean the build plate using the method recommended by the printer or build-surface manufacturer. Check bed levelling or mesh calibration, make sure the nozzle is clean, and ensure there is no leftover rigid filament causing partial blockage. If your printer maker recommends a specific surface or release method for flexible materials, use that.
Why: Flexible parts need a dependable first layer. Good bed preparation prevents prints from peeling up, shifting or bonding too aggressively to the surface.
- 4
Load the filament slowly and by hand guidance if needed
Cut the filament end neatly, start the loading routine, and guide the filament carefully into the extruder entrance so it does not snag. Feed it gently until extrusion begins cleanly. If the printer struggles to grab the filament, reduce idler pressure only if your printer manufacturer says this is adjustable and safe to do.
Why: Soft filament can bend at the point of entry during loading. Careful feeding helps it enter the hot end path cleanly instead of bunching up in the extruder.
- 5
Start with conservative slicer settings
Use the filament manufacturer’s recommended nozzle and bed temperatures as your starting point. In the slicer, choose a slow print speed, low or minimal retraction, moderate layer height and a simple first test model. If your slicer or printer maker offers a flexible-material profile, use that first and change only one setting at a time.
Why: Flexible filament is sensitive to pushing force and sudden direction changes. Conservative settings reduce buckling, stringing and uneven flow while making problems easier to diagnose.
- 6
Print a small test part and watch the first layers
Begin with a short, simple print such as a small calibration shape or a single-wall sample. Stay with the printer for the first layer and the early infill. Watch for poor adhesion, under-extrusion, filament grinding, skipping or bunching near the extruder.
Why: Most flexible-filament failures show up early. Catching them in a test print saves time and material before you commit to a longer job.
- 7
Fine-tune gradually based on the result
If the print is stringy, uneven or shows feeding problems, make one change at a time. Common adjustments include slowing the print further, reducing retraction, improving drying, or increasing cooling only if the filament maker supports it. Keep notes so you can repeat successful settings later.
Why: Flexible printing is highly dependent on the exact material and extruder. Small, controlled changes help you find a stable setup without introducing new variables.
- 8
Remove and finish the part carefully
Let the bed and part reach the condition recommended by your printer or build-surface manufacturer before removal. Lift the print gently with an appropriate tool if needed, and inspect the underside and walls for signs of poor adhesion or inconsistent extrusion before running multiple copies.
Why: Some flexible prints release best at a particular stage, while others can bond strongly to certain surfaces. Careful removal protects both the part and the build plate.
Why this works
Flexible filament prints successfully when feeding force is smooth and controlled. Because the material can compress and bend before it reaches the nozzle, slower speeds, reduced retraction, a supported filament path and dry material all reduce the chance of buckling and inconsistent extrusion.
Common mistakes to avoid
- Printing flexible filament with the same speed and retraction settings used for PLA
- Using filament that has absorbed moisture
- Trying a long, complex print before a small test part
- Ignoring gaps in the extruder path where the filament can buckle
- Using too much retraction, which can pull soft filament into a jam-prone position
- Assuming one TPU brand will print the same as another
Troubleshooting
Filament bunches up or wraps near the extruder instead of feeding
Stop the print, unload the filament and inspect the path from drive gear to hot end. Reduce print speed and retraction, and improve path support if your printer has a flexible-filament insert or direct-feed option.
Heavy stringing between features
Dry the filament first, then test lower retraction and slower travel-sensitive settings using the manufacturer’s guidance. Keep changes small and test one variable at a time.
Under-extrusion or inconsistent walls
Check for a partial nozzle clog, damp filament, excessive print speed or excessive idler tension. Re-run a small test print after each adjustment.
First layer will not stick
Clean the build plate, re-check bed levelling or probe offset, and confirm the bed surface and temperature match the filament maker’s recommendations.
Part sticks too strongly to the bed
Follow the build-surface manufacturer’s release guidance and avoid forcing removal. Some surfaces need a release layer or a different removal timing.
Surface looks rough and you hear popping from the nozzle
Dry the filament according to the manufacturer’s instructions and store it in a sealed dry container between prints.
Compare your options
Direct-drive extruder
Best for: Most users printing flexible filament regularly
Pros: Shorter filament path, usually easier feeding, often more forgiving with soft materials
Cons: Not every printer uses this design, and conversion may not be practical
Bowden extruder
Best for: Users whose printer is already well-tuned and has a constrained filament path
Pros: Can still work for some flexible filaments, especially firmer grades
Cons: Longer path increases compression and buckling risk, often needs slower settings and more tuning
Firmer flexible filament
Best for: Beginners new to flexible materials
Pros: Usually easier to feed and tune than very soft grades
Cons: Less stretch and softness in the finished part
Softer flexible filament
Best for: Users who need maximum flexibility and have a well-set-up printer
Pros: More compliant finished parts
Cons: Harder to feed consistently and more sensitive to setup
| Option | Best for | Pros | Cons |
|---|---|---|---|
| Direct-drive extruder | Most users printing flexible filament regularly | Shorter filament path, usually easier feeding, often more forgiving with soft materials | Not every printer uses this design, and conversion may not be practical |
| Bowden extruder | Users whose printer is already well-tuned and has a constrained filament path | Can still work for some flexible filaments, especially firmer grades | Longer path increases compression and buckling risk, often needs slower settings and more tuning |
| Firmer flexible filament | Beginners new to flexible materials | Usually easier to feed and tune than very soft grades | Less stretch and softness in the finished part |
| Softer flexible filament | Users who need maximum flexibility and have a well-set-up printer | More compliant finished parts | Harder to feed consistently and more sensitive to setup |
Alternatives
- Use a firmer flexible grade recommended by your printer manufacturer if very soft filament keeps buckling
- Switch to a printer profile or hardware setup designed for flexible materials
- If the part only needs slight flexibility, consider a less demanding material approved by your printer maker
Pro tips
- Start with a simple model before printing a functional part
- Change only one slicer setting at a time and keep notes
- If your printer has pressure advance or similar tuning features, use only values supported by the printer maker or tested profile
- Keep the spool feeding smoothly with minimal drag
- A clean nozzle and reliable first layer matter more with flexible filament than with many rigid materials
Safety notes
- Keep hands, hair and loose clothing clear of moving belts, fans and gears while observing the first layer
- The nozzle, hot end and bed can cause burns; let components cool as instructed before touching them
- Print in a well-ventilated area and follow the filament manufacturer’s safety guidance
- Use suitable tools when removing prints to avoid slipping and damaging the build surface or injuring yourself
What this guide does not cover: This guide covers general FDM/FFF printing with flexible filament and does not provide exact temperatures, speeds or drying schedules because these vary by filament brand, hardness and printer design.
Cost considerations
Flexible filament is often less forgiving than standard PLA, so failed prints can raise material costs if you skip drying and test prints. Starting with small calibration prints and storing filament properly usually saves money over time.
Frequently asked questions
Can I print flexible filament on a Bowden printer?+
Often yes, but it is usually harder than on a direct-drive machine. Success depends on how well the filament path is constrained, how soft the filament is, and whether you use slower, low-retraction settings.
Do I need to dry TPU before printing?+
In many cases yes, especially if the spool has been exposed to air. Follow the filament manufacturer’s drying and storage instructions rather than guessing.
Why does flexible filament string so much?+
Common causes are moisture, excessive nozzle temperature for that brand, unsuitable retraction settings and printing too fast. Dry the filament and start from the manufacturer’s recommended range.
Should I use the same settings as PLA?+
No. Flexible filaments usually need slower movement and different retraction behaviour. Use a dedicated flexible-material profile or the filament maker’s recommendations.
What is the best first test for flexible filament?+
A small, simple part with short print time is best because it lets you assess first-layer adhesion and feeding reliability without wasting much material.
Sources & references
Guidance on this page is traced to documented sources. Last checked 24 September 2026.
- Ultimaker Support · manufacturer
Supports general manufacturer guidance on using material profiles, printer-specific setup and flexible-material printing considerations.
- Prusa Knowledge Base · manufacturer
Supports practical guidance on flexible filaments, drying/storage concerns, and printer setup differences such as extruder behaviour.
Core handling principles stay fairly stable, but slicer features, printer profiles and manufacturer recommendations change over time.