Filament manufacturers print temperature ranges on every spool, but those ranges are wide by design. They cover every printer at every altitude at every ambient temperature. Your optimal temperature could be anywhere within that range, and finding the exact value with single test prints takes time. A temperature tower finds it in one print.
What a Temperature Tower Tells You
A temperature tower is a single print with multiple bands, each printed at a different temperature. When it’s done, you have a physical record of how the filament performs across a temperature range on your specific printer. You look at each band and pick the best-looking one.
What you’re optimizing for varies by material, but the general criteria are:
- Bridging: horizontal spans between two towers, printed in air
- Overhang angle: typically 45°, 60°, 75° stepped sections
- Surface finish: smoothness and layer line visibility
- Stringing: threads of filament between structures (shows up in retraction zones)
- Layer adhesion: visible on the overall structural integrity
Temperature affects all of these differently. Higher temperatures generally improve adhesion and reduce some defects while increasing others. Finding the balance is the point.
Getting the Temperature Tower Model
The standard source is a parametric temperature tower model. Look for one that includes bridges, overhangs, and retraction test sections. Popular variants have temperature ranges pre-baked into the model’s design.
Alternatively, use a slicer plugin that takes any test model and automatically inserts temperature change commands at set intervals. PrusaSlicer and Cura both have community scripts for this.
The model should cover your filament’s full temperature range. For PLA, that’s typically 190–230°C. For PETG, 220–250°C. For ABS, 220–260°C.
Setting Up the Print
Option 1: Generated Tower or Layer Commands
OrcaSlicer has a generated temperature calibration under its Calibration menu. Select the correct printer and filament, then choose a range within the material and printer limits. The project documentation explains the generated tower and how to inspect it.
In PrusaSlicer, slice the tower and use the layer slider in Preview. At each intended temperature transition, right-click the plus control and choose Add custom G-code, then insert the appropriate M104 S... command. Prusa’s linked instructions describe this layer-based insertion. The labels printed on a model do not change the temperature themselves.
Match every command to the corresponding band. Export and inspect the G-code before printing so the upper bands do not accidentally inherit the initial temperature.
Option 2: Manual Gcode Insertion
Open your exported gcode in a text editor. Find the layer change comments (;LAYER_CHANGE in PrusaSlicer, ;LAYER:X in Cura), calculate which layer corresponds to each temperature zone, and insert:
M104 S215 ; change to 215°CThis takes more time but works on any slicer.
Print Settings for the Tower
Use your standard profile settings, but:
- Speed: your normal print speed — don’t slow down, as speed affects how temperature behaves
- Cooling: your normal settings — don’t override, as cooling interacts with temperature
- Retraction: your current best-guess settings — you can tune these after finding the right temperature
The goal is to isolate temperature as the variable. Keep everything else constant.
Reading the Tower
Print the tower, then examine each band under good light. Use calipers or a loupe if needed.
Stringing: Look for fine threads of filament between the tower columns. Less stringing is better. Stringing usually decreases as temperature drops, but the coldest bands trade it for weak layer bonding and rough surfaces.
Bridging: Look at the flat horizontal spans. They should be tight and not sag. Better bridging performance is generally found at lower temperatures (cooler filament solidifies faster mid-air).
Overhangs: The angled sections should hold their shape without curling or drooping. Overhangs are usually better at lower temperatures with high cooling, but layer adhesion starts to suffer at the low end.
Surface quality: The outer walls should be smooth and consistent. Blobbing, rough surfaces, or visible layer lines can indicate wrong temperature.
Layer adhesion: Not directly visible in a temperature tower unless you intentionally break it after printing, but if the tower delaminates during printing, that band is too cold.
Typical Results
For PLA:
- 190–195°C: often too cold, poor adhesion, rough surface
- 200–215°C: usually the sweet spot for most PLAs
- 220–230°C: good adhesion but more stringing, less overhang quality
These are starting points. Your specific filament brand and printer cooling will shift the ideal range.
After the Tower: Refining
Once you’ve identified the temperature range that performs best, consider a second tower with 2°C increments to narrow down further. Use the finer comparison only if the initial bands leave a useful distinction to resolve.
Then update your material profile:
- Set print temperature to your optimal value
- Adjust retraction settings if you saw stringing (temperature affects optimal retraction)
- Run a second retraction test if needed
Material-Specific Notes
PETG: More forgiving than PLA. Optimal range is usually 230–240°C. Look for stringing as the primary indicator — PETG strings heavily when too hot.
ABS/ASA: Warping complicates the tower. Print in an enclosure. Focus on surface quality and layer adhesion. ABS tends to want higher temperatures than you’d expect.
TPU: Temperature matters less than retraction settings. Run a temperature tower first, then focus time on retraction.
Exotic materials: Carbon fiber, wood, metal-fill — the base polymer (usually PLA or PETG) determines the temperature range. Start with the base polymer’s optimal temperature and adjust from there.
Archiving Results
Keep a temperature tower for each filament you run. Label it with the filament brand, material, and color. When you open a new spool, run a quick tower — different batches from the same manufacturer can have slightly different optimal temperatures.
Start with filament in suitable condition, using 3D Filament Guide’s drying chart when conditioning is needed. Keep the dry-box and chamber setup consistent throughout the tower. The temperature you land on then feeds the next two steps: flow calibration at the chosen temperature, which sits downstream of both temperature and e-steps, and then pressure advance, whose optimum shifts with melt viscosity and therefore with whatever temperature this tower settles on. Towers are also the fastest way to isolate the temperature half of a stringing problem.
Where the tower sits relative to every other calibration, and which values it invalidates when you rerun it, is mapped in the 3D printer calibration order.
