Printer Filament Guide

Best Filament for the Elegoo Neptune 4

The open-frame, Klipper-driven bed-slinger that made 500 mm/s printing affordable.

Last updated: June 2026

The Neptune 4 is Elegoo's entry-level 2023 bed-slinger: an open-frame machine with a 225 × 225 × 265 mm build area, a dual-gear direct-drive extruder, and Klipper preinstalled for speeds up to 500 mm/s. It uses a 60W ceramic heater in a brass heating block, tops out at 300°C, and has auto bed leveling. It's fast and capable for the price, but it's an open frame with a brass nozzle, and both facts shape what you should feed it.

What the Elegoo Neptune 4 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 right now
Loading live prices...

Since the nozzle is brass, abrasive filaments (carbon-fiber and glass-fiber blends, glow-in-the-dark) will chew it up quickly. Budget about $12 for Elegoo's hardened steel nozzle kit before running those. With no enclosure, ABS and ASA are doable but warp-prone. You'll get far better results with a DIY enclosure or by sticking to PLA, PETG and TPU. The direct-drive extruder handles TPU and flexibles well, a genuine strength of this design.

Elegoo Neptune 4 specs that affect filament

Build volume
225 × 225 × 265 mm
Enclosure
Open frame
Heated chamber
No
Extruder
Direct drive (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 the printer for someone who wants fast, large-ish PLA and PETG prints on a tight budget and is comfortable tinkering. Anyone targeting carbon fiber or engineering plastics from day one is better served by the enclosed, hardened-nozzle Centauri Carbon.

Filament notes for the Elegoo Neptune 4

  • Ships with a brass nozzle, fine for PLA, PETG and TPU, but swap to the hardened steel kit (~$12) before any carbon-fiber or glass-fiber filament.
  • 300°C hotend covers PLA, PETG, ABS, ASA and TPU. It's not built for high-temp engineering plastics like PC-CF.
  • Open frame means no warp protection. ABS and ASA need a DIY enclosure or draft-free room to print reliably.
  • PLA and PETG are the sweet spot: fast, large parts at up to 500 mm/s with Klipper input shaping.
  • Direct-drive extruder handles TPU and flexibles well, including softer Shore hardnesses at moderate speed.
  • Dry PETG, TPU and any nylon before printing. There's no enclosure to buffer ambient humidity.
  • No active filtration, so print ABS/ASA in a ventilated space if you enclose it.
How SpoolHound tracks prices

The deals above are filtered to the materials the Elegoo Neptune 4 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

Can the Neptune 4 print carbon fiber filament?
Not safely with the stock nozzle. It ships with brass, which abrasive CF/GF filaments wear down fast. Install Elegoo's hardened steel nozzle kit (around $12) first, and keep in mind there's still no enclosure for warp-prone composites.
Is the Neptune 4 enclosed?
No. It's an open-frame bed-slinger with no enclosure or heated chamber. PLA, PETG and TPU print great. ABS and ASA need a DIY enclosure to avoid warping and layer splitting.
What's the maximum hotend temperature on the Neptune 4?
300°C, via a 60W ceramic heater. That covers PLA, PETG, ABS, ASA and TPU, but it's not intended for high-temperature engineering materials like polycarbonate composites.
Does the Neptune 4 run Klipper?
Yes, Klipper firmware is preinstalled on a quad-core mainboard, with input shaping and pressure advance enabling speeds up to 500 mm/s (250 mm/s is the practical default).

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