Printer Filament Guide

Best Filament for the Elegoo Neptune 4 Plus

Large-format open-frame Klipper printer: 320 × 320 × 385 mm of build space, same brass nozzle and 300°C ceiling.

Last updated: June 2026


The Neptune 4 Plus scales the Neptune 4 platform up to a 320 × 320 × 385 mm build volume while keeping Klipper firmware, a 5.2:1 dual-gear direct-drive extruder, and a 300°C hotend. It runs up to 500 mm/s (12,000 mm/s² acceleration) and uses multi-point auto bed leveling to keep the larger bed flat. Reach for it when part size is the priority and you don't want to step up to the Max.

What the Elegoo Neptune 4 Plus prints well

Recommended materials for this printer:

PLA PLA+ PETG TPU

No enclosure, so ABS, ASA, PC and nylon will warp and crack. Stick to PLA, PLA+, PETG and TPU for reliable prints. Carbon- and glass-fibre composites also need a hardened nozzle first.

Cheapest filament for the Elegoo Neptune 4 Plus right now
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Filament behavior tracks the rest of the Neptune 4 line: brass nozzle from the factory, so abrasive CF/GF blends need a hardened steel swap first. The bigger downside on a large open frame is warping. ABS and ASA on a 320 mm bed will lift at the corners without an enclosure, so most owners stick to PLA and PETG, where the size advantage really pays off. The direct-drive setup still handles TPU well.

Elegoo Neptune 4 Plus specs that affect filament

Build volume
320 × 320 × 385 mm
Enclosure
Open frame
Heated chamber
No
Extruder
Direct drive (5.2:1 dual-gear)
Max hotend temp
300°C
Stock nozzle
Brass, 0.4 mm
Abrasive-ready (CF/GF)
Needs hardened nozzle
Multi-material
Single colour

This is for makers printing big PLA and PETG parts (cosplay, large functional pieces, multi-part assemblies) who don't need a heated chamber. For abrasives or engineering plastics at this size, you'd want an enclosure plus a hardened nozzle, at which point an enclosed machine is the cleaner answer.

Filament notes for the Elegoo Neptune 4 Plus

  • Brass nozzle ships standard. Fit a hardened steel nozzle (Plus/Max kit) before carbon-fiber or glass-fiber filaments.
  • 300°C hotend covers PLA, PETG, ABS, ASA and TPU. Not for high-temp engineering plastics.
  • Large open-frame bed makes ABS/ASA especially warp-prone. Corner lift is common without an enclosure.
  • PLA and PETG are the strong suit. The 320 × 320 × 385 mm volume suits big single-piece prints.
  • 5.2:1 direct-drive extruder handles TPU and flexibles cleanly at moderate speeds.
  • Dry PETG, TPU and nylon before long large-format prints. Moisture defects compound over big parts.
  • Use a consistent first-layer routine. Bed adhesion across a large plate is the main failure mode for ABS/ASA.
How SpoolHound tracks prices

The deals above are filtered to the materials the Elegoo Neptune 4 Plus handles, aggregated from multiple retailers daily and normalised to cost per kg, so the cheapest in-stock option is always on top. Prices refresh every 24 hours and are region-aware, so switch your region in the nav. Click through to the retailer to confirm the live checkout price.

Frequently Asked Questions

How big can the Neptune 4 Plus print?
320 × 320 × 385 mm, a large build volume aimed at big single-piece prints. It keeps Klipper, direct drive and the 300°C hotend from the rest of the Neptune 4 line.
Can the Neptune 4 Plus handle carbon fiber filament?
Not with the stock brass nozzle. Install the hardened steel nozzle kit for the Plus/Max before running carbon-fiber or glass-fiber blends, and remember it's an open frame with no chamber heat.
Is ABS practical on the Neptune 4 Plus?
It's possible but warp-prone. On a 320 mm open-frame bed, ABS and ASA tend to lift at the corners without an enclosure. PLA and PETG are the reliable choices at this size.
What's the max hotend temperature on the Neptune 4 Plus?
300°C, covering PLA, PETG, ABS, ASA and TPU. It isn't designed for polycarbonate or other high-temperature engineering materials.

Different printer? See filament by printer for the rest of the lineup, or browse cheapest filament by material.