Material
PETG
Printer
Prusa Mk4

Short answer

The Prusa MK4 prints PETG at a 245 to 255 °C nozzle and a 75 to 85 °C bed, with low part cooling and a short direct-drive retraction. The MK4’s Nextruder is direct-drive, so retraction stays short, and PrusaSlicer’s built-in PETG profile gives you a ready starting point to tune from. PETG pulls moisture, though, so dry the spool and the MK4 lays it down clean.

Starting PETG settings for the MK4

These numbers suit a stock Prusa MK4 with the direct-drive Nextruder and the stock 0.4 mm nozzle. The nozzle, bed, and fan values track the Prusament PETG datasheet, which lists a 250 °C nozzle with a 10 °C window, an 80 °C bed, and 50 percent fan. The retraction baseline and the speed tuning are Marqilo starting points for the MK4.

Starting PETG settings for a Prusa MK4
SettingRecommendedWhy
Nozzle temp245 to 255 °C245 °C is a safe start; 255 °C helps the MK4 keep up at speed. The Prusament PETG TDS centers on 250 °C.
Bed temp75 to 85 °C80 °C gives strong grip on the smooth or textured sheet, per the Prusament PETG TDS.
Retraction0.4 to 0.6 mmDirect-drive Nextruder baseline. Tune within 0.4 to 0.6 mm for stringing.
Part coolingOff, then 50%Off for the first 2 to 3 layers, then 50 percent, per the Prusament PETG TDS. Drop toward 30 percent only if over-cooling appears.
First layer245 °C, 80 °C bed, 20 mm/sSlow and warm, so the PETG bonds to the sheet.
Print speed80 to 200 mm/sMarqilo starting point. The MK4 is fast, and the Prusament PETG TDS allows up to 200 mm/s.

How to adjust PETG settings

  1. Dry the PETG

    Run the spool at 55 °C for 6 hours in a dryer before you print, the Prusa-recommended PETG drying spec, since wet PETG strings and pops.

  2. Set the temperatures

    Nozzle to 245 °C and bed to 80 °C is a safe start that melts PETG clean on the MK4.

  3. Keep cooling low

    Run the part fan off for the first 2 to 3 layers, then set it to 50 percent, the Prusament PETG TDS value. Drop toward 30 percent only if over-cooling appears. Full cooling weakens PETG.

  4. Tune retraction

    Start at 0.5 mm on the Nextruder. If strings appear, step toward 0.6 mm until they clear.

What goes wrong

Most failed PETG prints on the MK4 trace to wet filament, too much cooling, and a sheet that grips too hard. Wet PETG pops and strings, so dry the spool. Full part cooling weakens the layers, so hold it to 50 percent, the Prusament PETG TDS value, and drop lower only if over-cooling appears. A smooth sheet without a release agent can chip when the print peels off, so use a glue-stick layer or the textured sheet. The PETG stringing guide walks through the cause-and-fix.

Frequently asked

What PETG nozzle temp for the Prusa MK4?
245 to 255 °C. Start at 245 °C and move to 255 °C at higher speeds. The Prusament PETG datasheet centers on 250 °C with a 10 °C window.
Does the MK4 need an enclosure for PETG?
No. PETG prints in the open on the MK4. An enclosure only helps in a cold, drafty room where the corners lift.
Do I need glue for PETG on the MK4?
On the smooth sheet, yes, as a release agent, since PETG can bond so hard it chips the surface. The textured sheet needs none.

For the material side, the PETG hub explains the filament in depth, and the filament storage guide covers keeping spools dry.

Related guides

Related

Cross-reference

Sources & methodology

4 citations · reviewed 2026-07-10
  1. 01Prusament PETG Technical Datasheet (TDS PDF): nozzle, bed, fan, speedaccessed 2026-07-06Tier 1
  2. 02Prusa Knowledge Base: PETG adhesion, shrinkage, and print guidanceaccessed 2026-07-09Tier 1
  3. 03PrusaSlicer documentation (built-in PETG print profile)accessed 2026-06-29Tier 1
  4. 04Prusa Knowledge Base: Drying filament (PETG 55 °C / 6 h)accessed 2026-07-10Tier 1
How we vetted this: every claim traces to a tiered source, Tier 1 (manufacturer, slicer, standards) first. Read the full sourcing and conflict-of-interest policy.