# What causes under-extrusion with certain filaments?

These PLA rows list 190–230 °C (374–446 °F).

A spool that under-extrudes while another brand does not is, in these threads, the wrong temperature and flow for that brand, a gear that is not gripping, a partial clog, or PLA softened inside a closed enclosure. One thread that looked sparse was a bridge printed with no supports.

Change temperature, flow, and the extruder grip for the spool that is failing, and leave the spool that already prints alone. [Clogs](/answers/clog) and [flow](/answers/flow) are the two mechanical pages. [SUNLU](/answers/brand_sunlu) is the brand in the side-by-side photo.

## One brand, one profile

[r/FixMyPrint 12c7d7c](https://www.reddit.com/r/FixMyPrint/comments/12c7d7c/) is Hatchbox printing cleanly and SUNLU under-extruded and discolored on the same gcode. The leading comment says every filament wants a slightly different temperature and extrusion speed, and that SUNLU runs slightly hotter than Hatchbox for PLA and PLA+. A score-17 comment keeps a profile per brand and names SUNLU, Inland, and Overture. A score-8 comment says raise the weak one by five or ten degrees, then check diameter with calipers and raise flow if the filament is thin. [SUNLU PLA](/brand/sunlu/pla) and [Hatchbox PLA](/brand/hatchbox/pla) both list 190–230 °C (374–446 °F) and a bed of 50–70 °C (122–158 °F). The slightly hotter SUNLU print is the comment. It is not a wider catalog cell. [Stringing](/answers/stringing) is the neighboring symptom when the temperature move goes too far.

## Not under-extrusion

[r/FixMyPrint 1py4pcc](https://www.reddit.com/r/FixMyPrint/comments/1py4pcc/) asks if the marks are under-extrusion or wet filament. The post is Bambu Basic PLA, a 0.4 mm nozzle, 220 °C (428 °F), a textured plate at 55 °C (131 °F), ironing on, and no supports. A score-19 comment says the bottom looks normal for bridges printed with no supports, and that ironing from someone else's settings will not be perfect. [Bambu PLA Basic](/brand/bambu-lab/pla-basic) lists 190–230 °C (374–446 °F) and a bed of 35–45 °C (95–113 °F). The post's 220 °C (428 °F) is inside the nozzle. The post's 55 °C (131 °F) is above the bed. [Drying](/answers/drying) is still the page when popping or a wet spool is the real complaint.

## Gear, host, and a closed box

[r/FixMyPrint una950](https://www.reddit.com/r/FixMyPrint/comments/una950/) asks if a repeating sparse pattern on a CR-10, with Cura's standard profile, is humid filament. A score-33 comment says the extruder gear is off center or wobbling, so one side of the teeth grips and the other does not.

[r/3Dprinting skq3dn](https://www.reddit.com/r/3Dprinting/comments/skq3dn/) is a spongy print while the extruder gear still advances the right length of filament. The comments this page retrieved blame a host that cannot parse gcode fast enough, including an old Raspberry Pi running OctoPrint and a Pi Zero. The original poster's own fix was not in that retrieved set.

[r/3Dprinting 105by21](https://www.reddit.com/r/3Dprinting/comments/105by21/) zipped a Creality enclosure on an Ender 5 Plus at 200 °C (392 °F) nozzle and 50 °C (122 °F) bed, and the PLA under-extruded. A score-25 comment says PLA is soft and the extruder gets hot enough to mangle it. A score-13 comment says PLA needs to cool and that the closed enclosure is for ABS or PETG. A score-9 comment names heat creep. [Clogs](/answers/clog) is the page when the filament softens above the melt zone. [PLA](/material/pla) is the material hub.

Updated 2026-10-17. Sources accessed 2026-10-17. Use case: Troubleshooting.

## Ranked filaments

| Rank | Filament | Nozzle | Bed | Price per kg |
| --- | --- | --- | --- | --- |
| 1 | SUNLU PLA | 190–230 °C (374–446 °F) | 50–70 °C (122–158 °F) | — |
| 2 | Hatchbox PLA | 190–230 °C (374–446 °F) | 50–70 °C (122–158 °F) | — |
| 3 | Bambu Lab PLA Basic | 190–230 °C (374–446 °F) | 35–45 °C (95–113 °F) | — |

## What the community says

r/FixMyPrint 12c7d7c is SUNLU under-extruded beside Hatchbox. The score-79 comment says each filament wants its own temperature and speed. A score-17 comment keeps a profile per brand. A score-8 comment says try five or ten degrees hotter, then measure diameter and raise flow if the filament is thin. r/FixMyPrint 1py4pcc asks if striations and strings are under-extrusion or wet filament. The post is Bambu Basic PLA at 220 °C (428 °F) and a textured plate at 55 °C (131 °F), ironed, printed without supports. A score-19 comment says the bottom looks normal for bridges with no supports, and that ironing needs its own tuning. r/FixMyPrint una950 asks if a repeating sparse pattern is humid filament. A score-33 comment blames an off-center extruder gear. r/3Dprinting 105by21 is PLA under-extruding once an enclosure is zipped, at 200 °C (392 °F) and 50 °C (122 °F). Comments say heat creep. r/3Dprinting skq3dn is a spongy print while the extruder gear still pushes the right length. Retrieved comments mention a Raspberry Pi that cannot feed gcode fast enough.

## Sources

- [Bambu PLA Basic technical data sheet](https://cdn.shopify.com/s/files/1/0584/7236/6216/files/Bambu_PLA_Basic_Technical_Data_Sheet_bf3411ce-be39-4db7-9669-1b4671d2196b.pdf?v=1734060943) (datasheet)
- [SUNLU brand site](https://sunlu.com/) (manufacturer)
- [Hatchbox brand site](https://hatchbox3d.com) (manufacturer)
- [Open Filament Database, SUNLU PLA](https://api.openfilamentdatabase.org/api/v1/brands/sunlu/materials/PLA/filaments/pla/index.json) (other)
- [Open Filament Database, Hatchbox PLA](https://api.openfilamentdatabase.org/api/v1/brands/hatchbox/materials/PLA/filaments/pla/index.json) (other)
- [Community source, r/3Dprinting skq3dn](https://www.reddit.com/r/3Dprinting/comments/skq3dn/) (reddit)
- [Community source, r/FixMyPrint 1py4pcc](https://www.reddit.com/r/FixMyPrint/comments/1py4pcc/) (reddit)
- [Community source, r/FixMyPrint 12c7d7c](https://www.reddit.com/r/FixMyPrint/comments/12c7d7c/) (reddit)
- [Community source, r/FixMyPrint una950](https://www.reddit.com/r/FixMyPrint/comments/una950/) (reddit)
- [Community source, r/3Dprinting 105by21](https://www.reddit.com/r/3Dprinting/comments/105by21/) (reddit)

HTML: https://filamentfacts.com/answers/underext