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· 5 min read
How to Choose a Nozzle Temperature
Heshan Fernando
Co-founder & COO
The spool says 200 to 230. That is a 30 degree window, and prints at either end look noticeably different. Somewhere in there is the right number for this spool, on this printer, at this speed.
Charts get you into the window. One test print gets you the number.
Read the symptoms, not the chart
Temperature problems announce themselves, and the symptoms point in a direction.
Too hot shows as stringing between separated features, blobbing and zits on the surface, drooping overhangs, and sometimes a shiny or over-glossy finish. Very hot can also cause heat creep, where softened filament jams above the melt zone.
Too cold shows as poor layer adhesion — the part splits along layer lines under light force — under-extrusion, gaps between perimeters, and sometimes clicking from the extruder as it struggles to push.
The useful distinction is that too cold affects strength while too hot affects appearance. A part that looks perfect and snaps along a layer line was printed too cool, and no amount of surface tuning will fix it.
| Symptom | Direction |
|---|---|
| Stringing, blobs, drooping overhangs | Too hot |
| Layers separating, under-extrusion, clicking | Too cold |
| Both at once | Wet filament, not temperature |
Stringing is often moisture, not heat
That last row matters. Filament absorbs water from the air, and PETG, nylon and TPU do so quickly.
Wet filament boils in the nozzle. The steam forces material out during travel moves, producing stringing that looks exactly like an over-temperature symptom — while the bubbles simultaneously weaken layer bonding, which looks like an under-temperature symptom.
Chasing that with temperature adjustments never converges, because both directions make one symptom worse. Drying the spool fixes it. A filament that printed well a month ago and strings now has almost certainly absorbed moisture rather than changed chemistry.
The temperature tower settles it
A tower is a single test print, tall and segmented, with a temperature change at each segment. Print one, look at where the surface and overhangs are best and where layer adhesion still holds, and use that temperature.
It takes about an hour and answers the question for that spool definitively. It is faster than the alternative of adjusting five degrees at a time across several failed prints, and considerably more reliable than a chart.
Worth doing per spool rather than per filament type. Pigments change flow behaviour, so two colours from the same manufacturer can want different temperatures — black and white in particular are frequently several degrees apart.
Other variables that shift the answer
Nozzle size. A larger nozzle pushes more material per second, so it usually needs a few degrees more at the same speed.
Print speed. Faster printing means less dwell time in the melt zone, which also wants a few degrees more.
Layer time. Small parts where each layer takes seconds do not cool between layers, so they print better at the cooler end of the range.
None of these are large individually, and together they explain why one number does not work across every print.
Bed temperature and first layer
The other temperature, and the one that decides whether a print starts at all.
Bed temperature affects adhesion, and adhesion failures account for a large share of failed prints. Too cool and the first layer lifts; too hot and some materials develop elephant foot, where the base spreads outward under the weight of what is above.
Most filaments print the first layer hotter at the nozzle as well, to improve bonding to the bed, and slower for the same reason.
Surface matters as much as temperature. Textured PEI, smooth PEI, glass and tape all have different adhesion characteristics with the same material, and a bed temperature that works on one may not on another. Cleanliness matters more than either — a bed with finger oil on it fails at any temperature.
Common mistakes to avoid
- Using a generic chart figure rather than the spool’s own label as the starting point.
- Chasing stringing with temperature when the filament is wet.
- Tuning for surface finish and ignoring layer adhesion, which is the property that matters structurally.
- Assuming two colours from the same brand behave identically.
- Changing temperature and speed together, so neither result is attributable.
How to do it with Nozzle Temperature Reference
The Nozzle Temperature Reference gives starting ranges with the symptom table.
- Choose the filament family for a starting range.
- Check the spool’s own label, which is more specific than any general chart.
- Print a temperature tower to find the number for that spool.
- Use the symptom table to decide direction if a print goes wrong later.
Other reference tools are in the tools directory.
Frequently asked questions
Why does the same filament need different temperatures?
Formulations differ between manufacturers and even between colours, since pigments change flow behaviour. Nozzle size and print speed shift it further, which is why one number does not cover every print.
What is a temperature tower?
A single test print with a temperature change at each segment. Print one, choose the segment with the best surface and adhesion, and the question is settled for that spool in about an hour.
Why is my print stringing at the recommended temperature?
Often moisture rather than heat. Wet filament boils in the nozzle and forces material out during travel, and dropping the temperature makes layer adhesion worse without fixing it. Dry the spool.
Final thought
Print one tower per spool. An hour spent once beats five days of five-degree adjustments across failed prints.