OrcaSlicer Stringing & Oozing Fixes: Ranked by Impact (2026)

The first time I ran a “stringing test” benchy farm with PETG, I came back to the printer twenty minutes later and laughed out loud. The pillars looked like a doll-sized harp. Strings everywhere. I did what every panicked user does: I cranked retraction from 0.8 mm to 4 mm, ran it again, and watched a fresh nest of strings appear, slightly thicker this time. I spent the next three nights chasing settings before I noticed the spool had been sitting on a shelf next to a humidifier since Christmas. The fix was not in the slicer. It was in a $40 dryer.

That experience is the spine of this guide. If you came here looking for “the magic retraction value for OrcaSlicer,” I’m going to disappoint you on purpose. There isn’t one. What there is, instead, is a stack of causes ranked by how often they’re actually the problem. Work the stack in order and you’ll stop chasing your tail. I’ve ordered the fixes by impact, not by how interesting they are to fiddle with, because I want you to spend an hour solving stringing rather than three weekends.

This article covers what stringing actually is (and is not), the impact-ranked fix list, OrcaSlicer’s stringing-related settings and where to find them in 2.3.x, material-specific drying and retraction tables, direct drive vs Bowden numbers, how to read the built-in retraction tower, and the false fixes that waste everyone’s time. Pour a coffee. We’re going deep.

Table of contents

• What stringing is vs oozing vs blobs
• Causes of stringing, ranked by impact
• OrcaSlicer’s stringing-related settings walkthrough
• Material-specific stringing patterns
• Direct drive vs Bowden retraction
• Drying guide table
• Stringing test prints (built-in)
• Common false fixes
• FAQ
• Final cleanup and CTA

What stringing actually is (and what it isn’t)

Half the forum threads I read mash three different artifacts into one word. Before you spend money on a dryer or rip apart your hotend, get the vocabulary right, because each of these has a different root cause and a different fix.

Stringing is the thin, hair-like filament strand dragged between two separate features of a print during a travel move. The nozzle moves fast across open air, the filament is still molten, and a strand peels out as the hotend leaves the part. You see this most clearly between the pillars of a stringing test or between the towers and ears on a multi-feature model. It’s a travel-move artifact. If your strings appear only during travel moves, you have a stringing problem.

Oozing is the broader phenomenon: a slow, continuous leak of plastic from the nozzle anytime the printer is not actively extruding. Residual pressure in the melt zone, thermal expansion of plastic inside the heatbreak, and moisture flashing to steam can all force molten filament out the orifice on their own. Stringing is one visible result of oozing during travels. Oozing also produces start-of-line zits, blobby seams where the perimeter restarts, and a noticeable puddle on the bed during long pauses or tool changes.

Blobs (also called zits, pimples, or scars depending on which forum you’re on) are localized aggregations of plastic at very specific points. Most of the time those points are the seam, the start and stop of a perimeter, layer changes, or the spot where a print paused for a filament swap. Blobs are not travel artifacts. They come from pressure-advance miscalibration, an imbalanced retract-and-restart, or seam-handling settings. If your “stringing problem” is actually a string of tiny zits running up the seam line, you don’t need this guide. You need the pressure advance and seam articles.

I want to flag this hard: stringing is not the same problem as Z-seams, vertical scars, or surface pimples. I see readers conflate them constantly. If your travel paths are clean but your seam line has bumps, close this tab and go read the seam material first. If your travel paths look like a spider’s leftovers and the seam itself is fine, you’re in the right place.

One more boundary worth setting. A small amount of stringing on a torture-test pillar print is normal. PETG will often show faint hairs that wipe off with a heat gun even after textbook calibration. You’re aiming for “good enough to clean up in ten seconds,” not “absolutely zero strands under a microscope.” Chasing perfection on a torture model leads to over-tuned settings that hurt actual prints.

Causes of stringing, ranked by impact (the 80/20 list)

I cannot overstate how much time I’ve watched people waste by starting at the bottom of this list. Retraction is the popular knob because it’s the obvious one, but it’s not where most stringing problems live. Work from the top, not the middle.

1. Wet filament. This is the #1 cause and the one that can’t be slicer-tuned around. Water trapped inside the filament flashes to steam at the melt zone, blows micro-bubbles out the nozzle, and oozes continuously regardless of how aggressive your retraction is. PETG, Nylon (PA), PC, PVA, and TPU are aggressively hygroscopic. PLA and ABS are less hungry for moisture but still affected. Fix: dry the spool before you touch the slicer.
2. Print temperature too high. Hotter plastic is runnier and oozes more. Try dropping nozzle temperature 5 to 10 °C and rerunning the test. OrcaSlicer’s Temperature Tower calibration is the right tool to find the lowest clean band.
3. Pressure advance not calibrated. Uncompensated pressure in the melt zone keeps pushing plastic after the extruder motor has technically stopped. This produces both end-of-line ooze and stringing on travels. Calibrate pressure advance before you touch retraction. If you skip this step you’re tuning retraction around a moving target.
4. Retraction distance wrong for your hardware. Too low and the pressure isn’t relieved before the travel starts. Too high (rare on modern direct-drive hotends) and you cause heat creep, grinding, or blobs at restart. Run the Retraction Test tower and pick the lowest clean value.
5. Retraction speed wrong for the firmware or extruder. Too slow and pressure can’t drop in time for the travel. Too fast and the extruder skips steps or grinds the filament. Bowden setups and weaker direct-drive steppers are especially sensitive here.
6. Travel speed too low. This one is counterintuitive. Slow travels mean the nozzle hovers over open air longer, which gives ooze more time to manifest as a visible strand. Bumping travel speed to 150 to 250 mm/s often kills marginal stringing instantly.
7. Z-hop adding ooze opportunity. Z-hop adds two short vertical moves to every travel. If your retraction is undertuned, Z-hop will visibly worsen stringing because the nozzle stays full of pressurized melt while it lifts and re-lowers. Tune retraction first, then enable Z-hop. OrcaSlicer’s Slope and Spiral lift types are gentler on stringing than the Normal Lift.
8. Nozzle gunk, partial clog, or worn nozzle. A burr around the orifice catches filament during travels and physically drags strands. A cold-pull cleans most partial clogs; brass nozzles wear out faster on abrasives like carbon fiber blends, glow-in-the-dark, or wood-filled PLA. If you’re three months into a CF spool with a stock brass nozzle, the nozzle is the problem.

Read that list again. If you skip steps 1 and 2 and jump straight to retraction, you will not fix a wet-filament print. I’ve tested this. I once dialed retraction from 0.8 mm to 6 mm on a soaking-wet roll of PETG just to prove the point to a friend. The strings got slightly shorter and slightly bumpier. They never went away. Twelve hours in the dryer fixed what no slicer setting could touch.

OrcaSlicer’s stringing-related settings walkthrough (2.3.x)

OrcaSlicer puts stringing-related controls in three places and sometimes hides one behind another. Here’s where to look, with the caveat that field labels occasionally shift between minor releases. Verify against the OrcaSlicer wiki at slice time if something looks renamed.

Filament Settings (per-filament, usually the right place to edit)

Most retraction parameters live under Filament Settings → Setting Overrides → Retraction. Per-filament settings override the printer-level defaults, which is what you want, because PETG and TPU need very different numbers than PLA on the same machine.

• Length on retraction (a.k.a. Retraction Length): how far the extruder pulls filament back during a travel. The single most-tuned setting in this whole guide.
• Retraction Speed: how fast the pull happens. Some printer profiles also expose a separate Deretraction speed, which is the speed at which filament is pushed back after the travel.
• Extra length on restart: a small amount of additional filament pushed back at travel end to recover from pressure loss. Keep this at 0 unless your calibration test specifically tells you otherwise. It’s a band-aid that usually masks a different problem.
• Z hop when retracting: vertical lift in mm during a travel.
• Z hop type / Vertical lift type: Auto, Normal Lift, Slope, or Spiral. Slope and Spiral move horizontally while lifting and are usually gentler on the print surface.
• Wipe while retracting: toggles a small wipe move during retraction to clear the nozzle tip.
• Wipe distance: distance in mm the nozzle wipes.
• Retract amount before wipe: percentage of total retraction performed before the wipe begins. Default is fine for most cases.
• Retract on layer change: should usually stay on. Disabling it to “save time” guarantees a string at every layer seam.

Printer Settings (per-machine defaults)

Under Printer Settings → Extruder → Retraction you’ll find the same field names as above but as printer-level fallbacks. Filament-level settings override these. Also on the printer tab: Travel speed and Travel speed Z, both of which matter for stringing.

Print/Process Settings (per-process tuning)

Under Print Settings there are several stringing-adjacent options that don’t live under “Retraction” but still affect strings.

• Quality → Avoid crossing walls when travel: routes travels around walls so any residual drool lands inside the part rather than as a visible string. Increases travel time but visibly reduces stringing, especially on PETG and TPU.
• Quality → Max travel detour distance: caps how far OrcaSlicer is allowed to reroute to avoid a wall. mm or % of direct distance.
• Quality → Reduce infill retraction: disables retraction during travel between infill segments. Leave this OFF if stringing is your problem; it’ll deposit visible hairs inside the print.
• Speed → Travel speed: the main travel speed setting.
• Others → Only retract when crossing perimeters: turn this OFF while chasing stringing. With it off, OrcaSlicer retracts on every travel, which is what you want during calibration.

The OrcaSlicer GitHub wiki pages on printer_extruder_retraction and printer_extruder_z_hop are the authoritative references. If a setting label looks different in your install, search for the wiki entry by the parameter’s internal name.

Material-specific stringing patterns

One of the biggest mistakes I see new users make is treating “retraction” as a single value to memorize. Each material has its own stringing fingerprint. PLA forgives sloppy tuning. PETG punishes it. TPU laughs at retraction entirely. Here’s the per-material breakdown, cross-referenced with the per-material setting guides on this site.

Ranges in the table are starting points, not prescriptions. The instruction to “run the retraction tower” applies to every row. The point of the table is to tell you which knob to turn first for a given material, not to give you a number to copy.

One material-specific note worth highlighting: TPU is the one filament where the standard advice gets inverted. Long retractions don’t reduce stringing on TPU. They cause the soft filament to buckle inside the extruder path and create a feed jam that strings even worse. If you’re printing TPU and your strings won’t quit, the answer is usually less retraction, not more, plus a thoroughly dried spool.

Direct drive vs Bowden retraction

The reason direct drive and Bowden setups need such different retraction numbers is mechanical. On a direct drive printer, the extruder motor is mounted right at the hotend, so when the motor reverses, the filament moves immediately and the pressure in the melt zone drops within a millimeter or two. On a Bowden setup, the extruder is mounted on the frame and connected to the hotend through a long PTFE tube. When the motor reverses, the filament has to travel the length of that tube before pressure in the melt zone actually drops, so you need a much longer retraction to achieve the same pressure relief.

The Bowden speed cap is real and worth respecting. Pushing retraction speed past 50 mm/s on a Bowden setup typically causes the PTFE tube to flex or compress under the load, which defeats the retraction. Worse, if your firmware caps the extruder velocity (Marlin’s M203 E or Klipper’s max_extrude_only_velocity), the slicer asking for 80 mm/s just gets silently clamped to whatever the firmware allows.

One thing I want to push back on: do not pick a number from this table and commit to it. Use the row that matches your setup as the tower test range and let the print tell you the right number. The single most reliable retraction value I’ve ever found for my Bambu P1S was 0.6 mm, which is at the low end of the modern direct-drive range, not the middle. The point of the test is to find the lowest value that prints cleanly. Going higher just wears the filament and risks heat creep.

Drying guide table (with sources)

This is the section that fixes most stringing problems, and it’s the section most beginners skip. If you take one thing from this article: dry your filament before touching slicer settings. Below is the per-material drying guide with the manufacturer or wiki source cited for each row. I deliberately don’t average sources together when they disagree, because I’d rather give you a range and let you decide than fabricate a precise number.

Three notes about reading this table. First, “drying time” assumes a properly heated dryer with reasonable airflow. A cheap dryer at 55 °C may not actually be holding 55 °C uniformly across the spool, and a saturated spool needs significantly more time than a slightly damp one. Second, the Nylon row caveat is important: 3DXTECH explicitly notes that over-drying nylon makes the printed parts brittle. Leave a little moisture in the system. Third, every consumer-grade dryer I’ve used runs cooler than its display claims, often by 5 to 10 °C. If yours has been “drying PETG at 65 °C” with no improvement, an external thermometer is worth $8.

Dryer hardware: what actually hits these temperatures

Not every dryer hits every row in the table above. Buying advice here is short and opinionated, based on what I’ve tested and what’s verified at manufacturer level.

• Sunlu FilaDryer S2 / S4 / SP2. Reliable ~55 to 70 °C range. Excellent for PLA, PETG, and ABS. Not enough for PC, Nylon, or CF blends. Most cost-effective starter dryer.
• Polymaker PolyDryer. Modular, chainable, quieter than the Sunlu, hits 75 °C in the standard tier with higher temps on the engineering tier. About 2.5x the Sunlu’s price but the build quality justifies it for daily users.
• Eibos Cyclopes / Eibos Easdry. Hits 70+ °C, dual-spool capacity, larger footprint. Good for users running two engineering filaments at once.
• Bambu Lab AMS 2 Pro. Active drying up to 65 °C. Works for PLA, PETG, ABS, TPU, and PVA. Not hot enough for PC, Nylon, or carbon-fiber blends. Bambu explicitly recommends the AMS HT for those.
• Bambu Lab AMS HT. Higher-temperature variant designed specifically for engineering plastics that exceed 65 °C drying requirements.

And the critical clarification that half the YouTube tutorials still get wrong: only the AMS 2 Pro and the AMS HT actively dry filament. The original AMS and the AMS Lite store filament with desiccant. They do not heat anything. If you’re running a stock AMS or an AMS Lite and assuming your PETG is being dried while it sits in the unit, it isn’t. The desiccant slows reabsorption; it doesn’t pull water out of a wet spool.

One more practical tip on storage. Dry filament re-absorbs moisture in hours in a humid room. After drying, either print straight from the dryer or move the spool into a sealed bag or sealed box with fresh desiccant. I keep my engineering filaments in 5-liter cereal containers with two big desiccant packs in each, and I refresh the packs in the oven monthly.

Stringing test prints in OrcaSlicer

OrcaSlicer ships with three built-in calibration tests that map directly onto the top of the impact-ranked list. Find them under Calibration in the menu bar.

Temperature Tower

Found under Calibration → Temperature Calibration. Sweeps nozzle temperature in 5 °C bands (default range varies by material profile). Print it, look for the lowest band that still bonds layers and prints cleanly without bridging failure. That’s your nozzle temperature. The lower you can go without losing layer adhesion or bridge quality, the less stringing you’ll see on travels. Full walkthrough on the temp tower guide.

Pressure Advance Calibration

Found under Calibration → Pressure Advance. Three modes: PA Line, PA Pattern, and PA Tower. Each gives you a value between 0 and 1 that compensates for the lag between extruder motion and actual flow. Calibrate this before the retraction tower. Skipping PA and going straight to retraction is the most common mistake in this whole workflow. Full walkthrough on the pressure advance guide.

Retraction Test

Found under Calibration → Retraction Test. Configurable start length, end length, and step size. The OrcaSlicer factory defaults are 0 mm to 2 mm with a 0.1 mm step, which is right for modern direct-drive setups. For Bowden you’ll want to change the range to roughly 1 mm to 6 mm with a 0.2 mm step. Click Calibrate and OrcaSlicer auto-generates a notched tower with each retraction value labeled on its section.

Here’s how to read the printed tower. Look at the gap between the two pillars on each level. Find the lowest section with no visible hairs between the pillars and no fuzz on the pillar surfaces. Note the retraction value labeled on that section. If multiple sections look identical, pick the lowest value. Going higher just wears the filament, increases the risk of heat creep, and can cause restart blobs as the cold plug at the heatbreak gets dragged into the melt zone. Full walkthrough on the retraction calibration guide.

Community torture tests

Once the built-in tests are dialed in, a multi-pillar torture STL (search Printables or Thingiverse for “stringing test”) is a good final pass. Print it at the settings you just calibrated, look at the result, and if it’s clean you’re done. If a torture print is still hairy after all three built-in calibrations and a dry spool, your problem isn’t a slicer setting. It’s hardware: a clogged nozzle, a worn nozzle, or a slipping extruder gear.

Common false fixes (don’t waste your weekend)

I keep a running list of “advice I see on forums that actively makes stringing worse.” Here it is.

• Lowering retraction without drying wet filament. Doesn’t help. Wet filament oozes from steam pressure, not pump pressure. The retraction is fighting the wrong battle.
• Cranking retraction speed past firmware limits. On many printers, exceeding the extruder’s velocity cap causes step skipping and filament grinding. Marlin’s M203 E and Klipper’s max_extrude_only_velocity both clamp the slicer’s requested speed. If your firmware caps it at 60 mm/s, setting OrcaSlicer to 100 mm/s does nothing useful.
• Z-hop without properly-tuned retraction. Z-hop without retraction creates stringing, because the nozzle stays full of pressurized melt while moving over open air. Use both or neither. Tune retraction first; add Z-hop only if you also have a scarring or layer-snag problem.
• Setting travel speed below 60 mm/s. Slower travels = more dwell over air = more time for ooze to manifest as a strand. Counterintuitive but real. Bump travel to 150 to 250 mm/s as a baseline.
• Raising retraction length forever. Over-retracting causes heat creep, restart blobs (cold plug dragged up into the heatbreak), and grinding. Stop at the lowest working value the tower gave you.
• Disabling “retract on layer change.” Saves a few seconds per layer and guarantees a strand at every layer seam. Don’t.
• Assuming any AMS dries filament. Only AMS 2 Pro and AMS HT actively dry. Standard AMS and AMS Lite are sealed storage only.
• Replacing the nozzle “just in case.” If your stringing tower has perfectly clean sections and the rest is hairy, the nozzle is fine. Replace the nozzle only when you’ve cleaned it, dried the filament, calibrated the slicer, and you still see drag marks on travels.

I want to expand on one of those because I’ve fallen for it myself. The “Z-hop without proper retraction” trap is the one that catches more intermediate users than any other. The logic feels right: if the nozzle is higher off the part during travels, there’s no way it can drag a string. But the physics doesn’t care. If retraction is undertuned, the nozzle is still full of pressurized melt at the moment it starts to lift, and that melt drools out during the lift and the lateral travel. A drooled-out strand of plastic on a Z-hop travel is just as visible as one on a flat travel. Tune retraction first. Add Z-hop only if you also need it for surface protection.

OrcaSlicer-specific tips that get glossed over

A few OrcaSlicer-specific behaviors worth knowing about, because they don’t always carry over from other slicers.

“Only retract when crossing perimeters.” Default is on for several profiles. Turn it OFF while you’re calibrating, because you want to see what happens on every travel. Once you’ve found a clean retraction value, you can turn this back on for production prints to save retraction wear.

“Reduce infill retraction.” Default is on for some profiles. This disables retraction during travel inside infill regions. Great for speed; terrible for stringing diagnostics. Turn it OFF while diagnosing, and only turn it back on if your final print quality is fine.

“Avoid crossing walls when travel.” Routes travels around walls instead of over them, so any residual drool lands inside the part rather than on the surface. It increases travel time but visibly cleans up PETG and TPU prints. I leave it on for everything except speed-benchy prints.

“Wipe before retract.” Performs a small wipe motion before pulling filament back. On PETG specifically, this is one of the single highest-impact settings after dryness and PA calibration. Don’t enable it for PLA where it just slows things down.

“Z hop type: Slope” or “Spiral.” The Normal Lift is a sudden vertical move. Slope and Spiral hop sideways as they lift, which is gentler on the print and reduces the “drool sideways” effect that Normal Lift can produce. If you need Z-hop, default to Slope.

“Max travel detour distance.” Cap on how far OrcaSlicer is allowed to reroute a travel around walls. Defaults are reasonable, but if you’re printing a part with very long unsupported spans and “avoid crossing walls” is on, OrcaSlicer might be making giant detours. Cap this at something sensible (say 50 mm or 20% direct distance) to keep travel time predictable.

Bringing it all together: my calibration order

For a brand-new filament I haven’t used before, here’s the order I run on my own printers. Adapt to taste.

1. Dry the spool. Use the table above. If I’m not sure of moisture state, I assume wet and dry. Cheap insurance.
2. Flow rate calibration. Quick first step to make sure I’m laying down the right amount of plastic.
3. Pressure Advance calibration. Eliminates the moving-target problem before retraction.
4. Temperature Tower. Find the lowest band with clean bridges and good layer bond.
5. Retraction Test. Run with the tower-range row that matches my hardware (see DD vs Bowden table). Pick the lowest clean value.
6. Print a real test piece. Multi-pillar stringing model or a small functional print. Look for hairs.
7. Adjust secondary settings if needed. Travel speed, wipe before retract, Avoid crossing walls.

This whole sequence takes about 4 to 6 hours on a Bambu-class machine including the drying. On an older Bowden setup, expect a full day. It’s a one-time investment per filament brand, and once you’ve got the numbers logged you can reuse them for every spool of that brand.

FAQ

How do I know if my filament is wet without a moisture meter?

Listen and watch. Wet filament pops and crackles audibly at the nozzle as the trapped water flashes to steam. The print surface often looks frosted or pitted rather than glossy. You’ll see continuous ooze even with retraction enabled, and stringing that survives every slicer setting you try. If the print sounds like rice krispies in milk, the spool is wet.

Can I dry filament in a kitchen oven?

You can, but it’s risky. Most kitchen ovens cycle the heating element on and off, which means the temperature swings by 10 to 20 °C around the setpoint. That’s bad news for materials with narrow drying windows like TPU or low-temp PLA. If you do it, use the lowest setting your oven offers, verify with an external thermometer, and check the spool isn’t deformed. A dedicated filament dryer is a better $50 to $80 investment than a ruined spool.

Is OrcaSlicer’s retraction tower better than Cura’s or Prusa’s?

It’s not categorically better; it’s more configurable. OrcaSlicer lets you set start, end, and step values explicitly, and it labels each notch on the printed tower. The output is the same kind of object you’d get from a community STL on Printables, but the in-app generation means you don’t have to re-set start G-code and per-feature settings. For most users, the built-in test is the right choice.

What retraction speed should I use on my Bambu P1S or X1C?

Bambu’s stock profiles use around 30 to 40 mm/s for most filaments. Their direct-drive extruder doesn’t benefit from going much faster, and the firmware caps it anyway. I leave retraction speed at the profile default and only tune retraction length.

My PETG strings even after drying for 12 hours at 65 °C. What now?

Three possibilities, in order. First, the dryer is running cooler than it claims; check with an external thermometer. Second, the spool was deeply saturated and needs another 6 to 12 hours. PETG that’s been open in a humid room for months can need 24+ hours. Third, your nozzle temperature is too high; try dropping 5 to 10 °C and rerunning. If all three are fixed and it still strings, the problem is mechanical: nozzle wear, partial clog, or extruder gear slip.

Does Z-hop help or hurt stringing?

Both, depending on retraction tuning. With well-tuned retraction, Z-hop helps because the nozzle isn’t dragging across the part on travels. With poorly-tuned retraction, Z-hop hurts because the nozzle still drools while it lifts and travels. Tune retraction first. Add Z-hop only if you need it for surface protection or to clear delicate features.

Should I use “Wipe while retracting” on PLA?

Usually no. PLA isn’t stringy enough to benefit from the wipe and it just adds time. Reserve “Wipe before retract” for PETG and TPU where it makes a visible difference.

Why does my print look fine until layer 30 and then it starts stringing?

Two likely causes. First, heat soak: the heatbreak and nozzle equilibrate after 20 to 30 minutes of printing, and the steady-state melt zone is hotter than the cold-start melt zone. If your nozzle temp is borderline, you’ll see ooze appear as the printer warms up. Drop nozzle temp 5 °C. Second, the part is moisture-sensitive and you’ve been printing from a damp spool that’s been exposed to room air long enough to absorb water at the surface. Dry it.

Is “Avoid crossing walls when travel” worth the speed cost?

For PETG and TPU, yes. The travel time penalty is usually 5 to 15% and the surface improvement is dramatic. For PLA on a fast printer, the cost-benefit is closer; I leave it on unless I’m racing a benchy.

Do carbon-fiber filaments need different retraction than their base material?

Slightly. CF blends are stiffer and the strands tend to be shorter, so you can get away with slightly less retraction than the base material. The bigger issue with CF is nozzle wear: carbon fiber chews through brass in 1 to 3 spools. Use a hardened steel or ruby nozzle, and re-run the retraction tower if you change nozzles.

My AMS Lite has been “drying” my PETG for three days. Why is it still stringing?

Because AMS Lite doesn’t dry. It stores filament with desiccant. The original AMS and the AMS Lite both lack active heating. Only AMS 2 Pro and AMS HT actively dry filament. This is the single most common AMS misconception I see in forum threads, and it wastes a lot of people’s time. Buy a dedicated dryer, or upgrade to AMS 2 Pro or AMS HT for engineering plastics.

Final cleanup, when to clean the nozzle, and where to go next

If you’ve made it through every step above and your stringing has dropped to “trivial wipe-off with a heat gun,” congratulations, you’re done. Log the retraction length, retraction speed, nozzle temperature, and pressure advance value somewhere you can find them later. I keep a spreadsheet keyed by filament brand and color, because the same “Polymaker PolyMax PETG” can have slightly different ideal values across colors and batches.

If you’re still seeing visible strings after a fully calibrated stack and a dry spool, it’s time to look at hardware. Run a cold pull to check for partial clogs: heat the nozzle to print temp, load a length of cleaning filament (or the same filament you’re using), let it sit at 220 °C for 30 seconds, cool to 90 °C, and pull. The shape of the cold-pulled tip tells you what’s stuck in the nozzle. Black flecks mean burned material; fibers mean cardboard or dust. Repeat until the cold pull comes out clean. If cold pulls don’t fix it, the nozzle is probably worn at the orifice (especially if you’ve been printing abrasives) and a new nozzle is the answer.

One last thing on giving up the slicer side. If you’ve calibrated PA, calibrated retraction, dried the spool, and still see strings, check the extruder gears. A worn or slipping extruder doesn’t pull the filament back the distance the slicer asks for, which manifests as undertuned retraction even though your number is correct on paper. Pop the extruder cover, look at the gear teeth for filament debris or wear flats. Clean or replace as needed.

For broader troubleshooting beyond stringing, our main OrcaSlicer troubleshooting guide covers layer adhesion, warping, under-extrusion, and first-layer problems. If you’re new to retraction calibration in general, start at the retraction calibration walkthrough. And if stringing turned out not to be your problem and you’re actually seeing zits at the seam, head to the first layer and surface defects guide for the right place to start.

Stringing is solvable. It’s just rarely solvable by jamming retraction up to 6 mm and hoping. Dry the spool, drop the temp, calibrate PA, run the tower, and the strings will go away. I’ve watched it happen on dozens of printers, and I’ve watched the wrong order waste weeks. Work the stack. Trust the process. Your next benchy farm will look like a model boatyard, not a doll’s harp.

Related OrcaSlicer guides

• OrcaSlicer Troubleshooting: Master Index of Every Common Fix
• OrcaSlicer Z-Wobble & Z-Banding: Diagnose and Fix (2026)
• OrcaSlicer Bed Adhesion Problems: Glue Strategies & Real Fixes (2026)
• OrcaSlicer Print Stops Mid-Print: Causes and Recovery Guide
• OrcaSlicer Tolerance & Fit Test: Functional Parts (2026 Guide)