Printer Filament Guide

Best Filament for the Prusa MK3S+

The legendary open-frame i3 with a massive install base. Slower than the MK4S, still a tank.

Last updated: June 2026

The MK3S+ is the printer that built Prusa's reputation, and its install base is still enormous. It's an open-frame i3 bed-slinger with a Bondtech dual-gear direct-drive extruder feeding an E3D V6 all-metal hotend, a 250 × 210 × 210 mm bed, and removable spring-steel sheets. It lacks the MK4S load cell, input shaping and high-flow nozzle, so it prints slower, but the mechanics are proven and parts are everywhere.

What the Prusa MK3S+ 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 Prusa MK3S+ right now
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On materials the MK3S+ behaves like the MK4S minus the speed: PLA, PETG and TPU are its bread and butter, and the V6's 300 C ceiling technically edges out the MK4S on paper. With no enclosure, ASA and ABS need draft protection and ideally the official enclosure to avoid warping. The stock V6 brass nozzle isn't made for abrasives, so swap to hardened steel for carbon- or glass-filled filament.

Prusa MK3S+ specs that affect filament

Build volume
250 × 210 × 210 mm
Enclosure
Open frame
Heated chamber
No
Extruder
Bondtech dual-gear direct drive (3:1) with E3D V6 hotend
Max hotend temp
300°C
Stock nozzle
E3D V6 brass nozzle, 0.4 mm (swappable)
Abrasive-ready (CF/GF)
Needs hardened nozzle
Multi-material
MMU2S/MMU3 (optional, up to 5 materials)

Buy or keep an MK3S+ if you already own one, want the most affordable route into the Prusa ecosystem and proven profiles, or value the gigantic community knowledge base over raw speed. For new buyers chasing speed and the latest features, the MK4S or CORE One make more sense.

Filament notes for the Prusa MK3S+

  • PLA, PETG and TPU are its sweet spot; the direct-drive Bondtech handles flexibles well for a machine of this era.
  • E3D V6 hotend is rated to 300 C, slightly higher on paper than the MK4S, but with no high-flow geometry it prints slower.
  • Stock V6 nozzle is brass, fine for PLA/PETG/ASA, but swap to hardened steel for any CF/GF filament.
  • Open frame and no chamber heat mean ASA/ABS want the optional enclosure for anything beyond small parts.
  • Spring-steel PEI sheets (smooth/textured/satin) cover PLA, PETG and ASA; glue stick helps tame PETG adhesion.
  • MMU2S/MMU3 add up to five-material printing, though multi-material is slower and more finicky than on the MK4S.
  • Keep PETG and any filled filament dry, since older firmware/hardware is less forgiving of wet filament stringing.
How SpoolHound tracks prices

The deals above are filtered to the materials the Prusa MK3S+ 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

Is the MK3S+ still worth buying in 2026?
For new buyers chasing speed, the MK4S or CORE One are the better pick. The MK3S+ still makes sense if you want the most affordable entry into Prusa's ecosystem, value the huge community and parts availability, or already own one and want to keep it running.
What filaments does the MK3S+ print best?
PLA, PETG and TPU are its strengths thanks to the Bondtech direct-drive extruder. ASA and ABS work but need draft protection or the official enclosure since the frame is open with no heated chamber.
Can the MK3S+ print carbon-fiber filament?
Only after swapping the stock E3D V6 brass nozzle for a hardened steel one. Brass wears quickly against carbon- and glass-filled filaments, so a hardened nozzle (and ideally a larger orifice) is required for those materials.
How hot does the MK3S+ hotend get?
The E3D V6 all-metal hotend is rated to 300 C with the bed up to 120 C. That covers PLA, PETG, ASA, ABS and filled nylons, but not true high-temp materials, and there's no actively heated chamber.

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