Print with PETG
PETG is a practical, tough and useful FDM material, but it is not as carefree as PLA. It has excellent layer adhesion and better heat resistance than PLA, but it can string, blob, stick too hard to the build plate and collect on the nozzle if treated badly.
This page focuses on practical PETG printing on Bambu Lab printers such as the P1S. It is written as a workshop guide rather than a perfect universal profile.
Contents
Basic approach
PETG prints best when it is dry, controlled and not forced beyond the hotend's ability to melt material consistently. Compared with PLA, PETG is more sensitive to moisture, nozzle buildup, stringing and support scarring.
Good PETG workflow
- Dry the filament if there is any doubt.
- Select the correct printer, plate, nozzle and filament profile in Bambu Studio.
- Use a PETG or PETG HF profile, not a PLA profile.
- Check the build plate selection carefully.
- Use the preview to inspect supports, bridges, seams and top surfaces.
- Slow down visible surfaces if the part needs to look clean.
- Do not chase maximum speed until the filament behaves.
Drying PETG
Drying is one of the most important PETG topics. Wet PETG can string, pop, hiss, foam, make rough surfaces, leave blobs and generally pretend to be five different slicer problems at once.
| Symptom | Could be wet PETG? | What to do |
|---|---|---|
| Fine hairs and stringing everywhere | Very possible | Dry filament before deep slicer tuning. |
| Popping or sizzling from nozzle | Very likely | Dry filament. |
| Rough, foamy or inconsistent surface | Likely | Dry filament and check temperature/speed. |
| Random blobs | Possible | Dry filament and check nozzle buildup. |
| Weak layer bonding | Possible | Dry filament, then check speed and temperature. |
Start with the correct profile
PETG needs a PETG profile. In Bambu Studio, start with the built-in profile that best matches the filament: Bambu PETG HF for Bambu PETG HF, Generic PETG for unknown ordinary PETG, and a specific PETG-CF profile for carbon-fiber reinforced PETG.
| Filament | Profile direction | Notes |
|---|---|---|
| Bambu PETG HF | Use matching Bambu profile | Designed for higher speed than ordinary PETG. |
| Unknown ordinary PETG | Start with Generic PETG | Safer than assuming it can run like high-flow PETG. |
| PETG Translucent | Use matching or conservative PETG profile | Slow down if surface consistency or light transmission matters. |
| PETG-CF | Use PETG-CF profile | Use hardened nozzle and treat as abrasive. |
Speed and flow
PETG usually does not like being bullied as hard as PLA. High-flow PETG can be fast, but ordinary PETG often prints cleaner at moderate speed. If you push PETG too hard, the result can be weak, rough, stringy or blobby.
| Bambu Studio Speed setting | Clean PETG | Functional PETG | Fast PETG HF | Why it matters |
|---|---|---|---|---|
| Initial layer | 25–40 mm/s | 30–45 mm/s | 35–50 mm/s | First layer control matters. PETG can stick too hard or too poorly depending on surface. |
| Initial layer infill | 50–80 mm/s | 60–90 mm/s | 70–105 mm/s | Can be faster than the first outline, but keep it controlled. |
| Outer wall | 60–100 mm/s | 80–130 mm/s | 120–180 mm/s | Controls visible surface and dimensional quality. |
| Inner wall | 100–160 mm/s | 140–220 mm/s | 180–260 mm/s | Can be faster because it is less visible. |
| Sparse infill | 120–200 mm/s | 180–260 mm/s | 220–320 mm/s | Good place to save time if flow keeps up. |
| Internal solid infill | 100–160 mm/s | 140–220 mm/s | 180–260 mm/s | Supports top surfaces and solid areas. |
| Top surface | 50–90 mm/s | 70–120 mm/s | 90–150 mm/s | Slow down if the top looks rough, torn or inconsistent. |
| Gap infill | 60–100 mm/s | 80–130 mm/s | 100–160 mm/s | Small squeezed regions can get messy if printed too fast. |
| Support | 100–160 mm/s | 120–200 mm/s | 160–240 mm/s | Support can be faster, but bad support can scar the part. |
| Support interface | 40–80 mm/s | 50–100 mm/s | 70–120 mm/s | Interface quality affects the underside of the real part. |
| Travel | 300–500 mm/s | 350–500 mm/s | 400–500 mm/s | Fast travel is fine, but stringing may increase on wet or hot PETG. |
Cooling
PETG needs less cooling than PLA. Too much cooling can weaken layer bonding, while too little cooling can make overhangs ugly and details soft. PETG cooling is a balance, not a fan-to-maximum contest.
| Problem | Possible cooling direction | Notes |
|---|---|---|
| Weak layer bonding | Less cooling, slower speed or warmer profile | PETG strength depends heavily on good layer bonding. |
| Ugly overhangs | More cooling or slower overhangs | Do not overdo it if the part needs strength. |
| Droopy bridges | More bridge cooling and slower bridge speed | PETG bridges usually need more help than PLA. |
| Small features look soft | More cooling or longer layer time | Small parts may stay hot too long. |
Bed adhesion
PETG bed adhesion can be too weak or too strong. Too weak gives lifting corners. Too strong can damage build surfaces. Always use the correct plate selection and follow the surface guidance for the plate.
Good first checks
- Make sure the selected plate in Bambu Studio matches the physical plate.
- Clean the plate.
- Use a suitable release layer if your build surface requires it.
- Use a brim for tall, narrow or corner-lifting parts.
- Let the plate cool before removing the part.
Nozzle choice
A 0.4 mm nozzle is the default for PETG. A 0.6 mm nozzle is often excellent for functional PETG parts because thicker lines and walls suit practical prints. PETG-CF should use a hardened nozzle.
| Nozzle | Use for PETG | Avoid for |
|---|---|---|
| 0.2 mm | Small plain-PETG details if necessary | PETG-CF, filled PETG, fast functional parts |
| 0.4 mm | General PETG printing | Very large parts where speed matters more than detail |
| 0.6 mm | Brackets, holders, enclosures, stronger walls | Tiny details and small text |
| 0.8 mm | Large chunky PETG parts | Fine visual work |
Quality settings
In Bambu Studio, the Quality tab controls layer height, line width, seam behavior and related surface/detail settings. For PETG, do not chase microscopic detail unless the part actually needs it. PETG is usually at its best as a practical material.
| Quality area | Clean PETG | Functional PETG | Notes |
|---|---|---|---|
| Layer height | 0.12–0.20 mm | 0.20–0.28 mm | Use smaller layers for appearance, larger layers for practical parts. |
| Initial layer height | Default/profile value | Default/profile value | Keep first layer reliable. |
| Outer wall line width | Default or slightly conservative | Default or wider with larger nozzle | Do not make thin PETG walls if strength matters. |
| Seam position | Hide on rear/corner | Away from loaded areas | PETG seams can blob more than PLA seams. |
| Scarf seam options | Try if seam is ugly | Use only if it helps the part | Good for visual tuning, but test before trusting. |
Strength settings
PETG is good for functional parts, but strength still comes from geometry, walls and orientation. More infill alone is not enough.
| Strength area | General PETG | Stronger PETG | Notes |
|---|---|---|---|
| Wall loops | 3 | 4–6 | Walls are usually more useful than excessive infill. |
| Top shell layers | 4–5 | 5–7 | Useful for top closure and loaded top surfaces. |
| Bottom shell layers | 3–4 | 4–6 | Useful for bases, screw regions and mounts. |
| Sparse infill density | 10–20% | 20–35% | Above this, redesign or more walls may help more. |
| Sparse infill pattern | Gyroid, cubic or adaptive cubic | Gyroid, cubic or adaptive cubic | Good general-purpose choices for functional parts. |
Supports
PETG supports can be stubborn because PETG bonds strongly. Support removal can be worse than PLA, and support scars on visible surfaces can be ugly. When possible, design or orient the part to avoid supports.
Support strategy
- Rotate the model to reduce support before touching settings.
- Use chamfers instead of unsupported flat ledges where possible.
- Avoid support contact on visible faces.
- Use support interface carefully.
- For multi-material printing, PLA can sometimes work as a PETG support interface because PLA and PETG do not bond strongly to each other.
AMS and PETG
PETG can work in the AMS, but it should be dry and on a spool that feeds well. PETG is usually more sensitive to moisture than PLA, and wet PETG in multi-material prints can create stringing, purge problems and ugly color/material transitions.
- Dry the spool before important AMS prints.
- Avoid brittle or badly wound spools.
- Expect more purge tuning than with PLA if visual quality matters.
- Be careful with abrasive PETG-CF.
- Do not assume every third-party spool behaves nicely in the AMS.
Pretty PETG prints
PETG can look good, especially translucent or glossy parts, but it usually needs more patience than PLA. Pretty PETG means dry filament, slower visible walls, controlled top surfaces and careful seam placement.
Useful directions
- Dry the filament.
- Slow outer walls.
- Slow top surfaces.
- Place seams deliberately.
- Reduce supports on visible faces.
- Use conservative speeds for translucent PETG.
- Check for nozzle buildup before it drops a blob onto the print.
Functional PETG prints
Functional PETG is where the material shines. It is good for brackets, holders, covers, tool mounts, electronics enclosures and parts that need to survive handling better than PLA.
For stronger PETG parts
- Use more walls.
- Use a sensible infill pattern and density.
- Orient the part so layer lines are not pulled apart.
- Use radiused corners around loaded features.
- Make screw bosses generous.
- Consider 0.6 mm nozzle for larger functional parts.
- Use PETG-CF if stiffness matters and you have a hardened nozzle.
Common problems
| Problem | Likely causes | First things to try |
|---|---|---|
| Stringing | Wet filament, too hot, travel behavior | Dry filament, use correct profile, reduce temperature only after drying |
| Nozzle blobs | Nozzle buildup, too much ooze, wet filament | Dry filament, clean nozzle, slow down, check flow |
| Rough surface | Wet filament, too fast, flow limit | Dry filament, slow visible walls, check volumetric flow |
| Poor bed adhesion | Dirty plate, wrong plate profile, not enough contact area | Clean plate, correct plate selection, brim |
| Too much bed adhesion | Wrong surface, no release layer where needed | Use correct plate guidance, let plate cool, use release layer if recommended |
| Ugly overhangs | Too hot, too fast, not enough cooling | Slow overhangs, adjust cooling, improve orientation |
| Supports hard to remove | PETG bonds strongly | Change orientation, tune support interface, consider PLA interface in multi-material setup |
| Weak part | Bad orientation, too few walls, too fast, too much cooling | Reorient, add walls, slow down, check cooling and layer bonding |
| Clogging | Particles, PETG-CF, wrong nozzle, degraded filament | Use hardened/larger nozzle for CF, avoid tiny nozzles with filled materials |
Quick recipes
General PETG part
- 0.4 mm nozzle.
- Matching PETG or Generic PETG profile.
- Dry filament if unsure.
- 0.20 mm layer height.
- 3 walls.
- 10–20% infill.
- Moderate speed.
Clean-looking PETG part
- Dry filament.
- 0.12–0.16 mm layer height.
- Slow outer wall.
- Slow top surface.
- Deliberate seam placement.
- Avoid support on visible faces.
Functional PETG bracket
- 0.4 or 0.6 mm nozzle.
- Dry filament.
- 0.20–0.28 mm layer height.
- 4–6 walls.
- 20–35% infill.
- Orient for load direction.
- Add fillets around loaded corners.
Translucent PETG diffuser
- Use dry translucent PETG.
- Print slower for consistent walls.
- Use fewer walls for more light transmission.
- Avoid dense infill if light should pass through.
- Expect frosted/translucent, not glass-clear.
Summary
- PETG is tougher and more heat tolerant than PLA, but messier to print.
- Dry PETG before serious troubleshooting.
- Use a proper PETG profile, not PLA settings.
- Moderate speeds usually give cleaner PETG than maximum speed.
- Slow outer walls, top surfaces, bridges and support interfaces for better quality.
- Use more walls before relying on huge infill numbers.
- Be careful with build plate adhesion; PETG can stick too hard.
- Use a hardened nozzle for PETG-CF.
Related pages: PETG filament guide, 3D printing material guide.