How Do I Fix Stringing in 3D Printing?

If your prints look like they're covered in spider webs, here's the fix:

The short answer: Tune your retraction settings (distance + speed), lower your temperature 5-10°C, and dry your filament. Wet PETG and PLA string like crazy. Fix those three and stringing disappears.

What causes stringing?

Stringing happens when melted filament oozes out while the nozzle moves between parts. Three main causes:

Weak or no retraction - Filament doesn't get pulled back into the nozzle before travel moves.

Temperature too high - Filament is too runny and drips out.

Wet filament - Moisture turns to steam and pushes filament out. If you hear popping, your filament is wet.

1. Retraction settings (start here)

Retraction is your first line of defense. When the nozzle travels without printing, the extruder pulls filament back slightly to stop oozing.

Starting retraction settings by printer type

Printer Type Retraction Distance Retraction Speed
Bowden (Ender 3, CR-10, etc.) 4-6mm 40-60mm/s
Direct Drive (Prusa, Voron, etc.) 0.5-2mm 25-45mm/s

How to tune retraction distance

  1. Print a retraction test tower (search "retraction test" on Thingiverse/Printables)
  2. Start with the baseline above for your printer type
  3. Increase distance by 0.5mm if you still see strings
  4. Stop when strings disappear - more retraction isn't better (causes clogs and grinding)
  5. Don't go past 8mm on Bowden or 3mm on direct drive

Where to find retraction settings in your slicer

Cura:

  • Settings → Search for "retraction"
  • Enable "Retraction Distance" and "Retraction Speed"
  • Also check "Combing Mode" - set to "Not in Skin" or "Off"

PrusaSlicer / SuperSlicer:

  • Printer Settings → Extruder 1
  • Look for "Length" (distance) and "Speed" under Retraction

Simplify3D:

  • Edit Process Settings → Extruder tab
  • Set "Retraction Distance" and "Retraction Speed"

2. Temperature tuning

Too hot? Stringy mess. Too cold? Poor layer adhesion and clogs. You need to find the sweet spot.

Check the temperature range on your spool (like 190-220°C for PLA). Start in the middle, then drop 5°C at a time until stringing stops. Don't go too low or your layers won't stick together.

Temperature tower test

  1. Download a temperature tower STL (search "temperature tower" on Printables)
  2. Use a calibration script or manually change temps every few layers
  3. Print starts hot (like 220°C) and drops 5°C every section (215, 210, 205, etc.)
  4. Find the lowest temp with good layer adhesion and minimal stringing
  5. That's your optimal print temperature for that roll

Typical temperature ranges

PLA:

  • Range: 190-220°C
  • Sweet spot for no stringing: 195-205°C
  • Lower = less stringing, but watch for layer separation

PETG:

  • Range: 230-250°C
  • Sweet spot: 235-245°C
  • PETG strings more than PLA - retraction is critical

TPU (flexible):

  • Range: 220-240°C
  • Sweet spot: 225-235°C
  • Print slow (20-30mm/s) and disable retraction or use minimal (0.5-1mm)

ABS:

  • Range: 230-250°C
  • Sweet spot: 240-245°C
  • Needs an enclosure - drafts cause warping, not stringing

3. Travel speed and Z-hop

Faster travel means less time for ooze to form strings.

Travel speed

  • Set travel speed to 150-200mm/s (much faster than print speed)
  • In Cura: Search "Travel Speed"
  • In PrusaSlicer: Print Settings → Speed → Travel

Z-hop (lift Z)

Lifts the nozzle slightly during travel moves so it doesn't drag through existing print.

  • When to use: Complex prints with lots of small parts or tall towers
  • When to avoid: Z-hop can make stringing worse if your Z-axis is slow
  • Setting: 0.2-0.4mm lift is enough
  • Enable in slicer under "Z Hop" or "Lift Z"

4. Filament moisture (a hidden cause)

Wet filament strings like crazy, even with perfect retraction settings.

PLA, PETG, and Nylon absorb moisture from the air. When wet filament hits the hot nozzle, water turns to steam and forces filament out, causing oozing and poor surface quality.

Signs your filament is wet

  • Excessive stringing that wasn't there before
  • Popping or hissing sounds during printing
  • Rough surface finish or blobs
  • Brittle prints that snap easily

How to dry filament

  1. Food dehydrator: 50°C for 4-6 hours (PLA/PETG)
  2. Filament dryer box: Use a dedicated dryer (Sunlu, EIBOS, etc.)
  3. Oven: 50°C for 4-6 hours - use an oven thermometer, ovens lie about temp
  4. Prevention: Store filament in sealed bags with desiccant packs

Quick moisture test

Print a small test object. If you hear popping/hissing or see steam coming from the nozzle, your filament is wet. Dry it before trying more retraction fixes.

5. Slicer tweaks for stubborn stringing

If retraction and temperature aren't enough, try these slicer settings:

Advanced stringing fixes

Minimum travel distance before retraction:

  • Only retract on travels longer than X mm (default 1.5mm)
  • Too many retractions cause grinding and clogs
  • Increase to 2-3mm if you're getting extruder clicking

Wipe/Coast settings:

  • Coasting: Stops extruding slightly before the end of a line (uses residual pressure)
  • Wipe: Moves nozzle along the last printed line after retraction to wipe off ooze
  • Both help reduce blobs and minor stringing
  • Enable in Cura under "Coasting" and "Wipe Distance" (usually 0.5-1mm)

Combing mode:

  • Controls whether nozzle travels over infill or takes shortest path
  • Set to "Not in Skin" - avoids crossing outer walls where strings are visible
  • Or set to "Off" if you have good retraction

Max comb distance with no retract:

  • In Cura, set to 10-20mm
  • Forces retraction on long travels even when combing

6. PETG-specific stringing tips

PETG strings way more than PLA. It's stickier and stays molten longer.

PETG anti-stringing checklist

  • Lower temperature: Try 235°C instead of 245°C
  • Increase retraction: PETG needs 1-2mm more than PLA on the same printer
  • Dry it thoroughly: PETG absorbs moisture fast - 6+ hours at 65°C
  • Slow down first layer: PETG squishes and strings if first layer speed is too high
  • Disable Z-hop: PETG is sticky and Z-hop can make it worse
  • Enable coasting and wipe: Helps with the end-of-line blobs that turn into strings

Even with perfect settings, PETG will have some minor stringing. That's normal. Clean it up with a heat gun (quick pass) or just pull the strings off by hand.

7. When to ignore stringing

A few thin strings are fine if:

  • They're easy to remove with tweezers or a quick heat gun pass
  • They're only on interior/hidden parts
  • Your print is functional and strings don't affect fit or strength

Chasing perfect zero stringing with extreme retraction settings can cause other problems like clogs, grinding, and under-extrusion. Find the balance that works for your prints.

8. Nozzle and hardware issues

Sometimes stringing isn't a settings problem - it's hardware.

Hardware causes of stringing

  • Worn or damaged nozzle: Nozzle opening gets rough or enlarged over time. Replace brass nozzles every 3-6 months.
  • Partial clog: Filament builds up inside the nozzle. Do a cold pull or replace the nozzle.
  • Heat creep: Hot end cooling fan not working - filament melts too high up in the hot end. Check your fan.
  • PTFE tube gap (Bowden): Gap between PTFE tube and nozzle lets filament ooze. Reseat or replace PTFE tube.
  • Loose nozzle: If nozzle isn't tight, filament leaks. Tighten nozzle while hot (use proper tools, don't overtighten).

Quick diagnostic checklist

  1. ✓ Retraction enabled and tuned for your printer type (Bowden vs direct drive)?
  2. ✓ Printed a temperature tower to find optimal temp?
  3. ✓ Travel speed set to 150mm/s or higher?
  4. ✓ Filament dry (no popping/hissing sounds)?
  5. ✓ Nozzle clean and not worn out?
  6. ✓ Tried a retraction test print to verify settings?
  7. ✓ Coasting/wipe enabled for stubborn cases?

The tuning process

Here's the order to tackle stringing:

  1. Enable retraction with baseline settings for your printer type
  2. Dry your filament if it's been sitting out for weeks
  3. Print a temperature tower and pick the lowest good temp
  4. Print a retraction test and tune distance in 0.5mm increments
  5. Increase travel speed to 150-200mm/s
  6. Try coasting/wipe if you still see minor strings

Don't change everything at once. Adjust one setting, print a test, evaluate. That's how you learn what actually makes a difference.

Bottom line

Tune your retraction (4-6mm Bowden, 0.5-2mm direct drive), lower your temps, and dry your filament. Fix those three and stringing stops. PETG will always string a little-that's normal. Just pull off the strings and keep printing.

Related: Why won't my 3D print stick to the bed?