How to Edit Start G-code in PrusaSlicer

Start G-code in PrusaSlicer lives under Printer Settings > Custom G-code, in the Start G-code box. It runs after the initial temperature commands and before the print starts, and it is where homing, bed leveling, and any prime routine go. If you do not see the section, switch the mode toggle in the top-right corner to Expert.

Where to edit it

1. Open the Printer Settings tab.
2. Select Custom G-code.
3. Edit the Start G-code box.

Keep a copy of the original before you change anything, since this block runs before every print on that profile.

Use placeholders, not fixed numbers

PrusaSlicer replaces curly-brace variables at slice time. Prefer them over hard-coded values so the start sequence stays correct across materials:

• {first_layer_temperature[0]}: nozzle temperature for the first layer.
• {first_layer_bed_temperature[0]}: bed temperature for the first layer.

If you hard-code a temperature, it will not follow when you switch filament, which is a common cause of first layers printing too hot or cold.

Common additions

• A prime line: move to the front edge, extrude a bead to prime the nozzle, then wipe, so the first real perimeter starts clean.
• A heat soak: a short dwell after heating so an enclosed chamber or the bed stabilizes before printing.

Why this matters for a print farm

Start G-code is per-printer, and a mistake in it affects every job that machine runs. Keeping each machine's start sequence correct and consistent is a fleet-level concern, not a per-job one.

Printago runs each machine's start sequence from its own centrally managed profile, so a fix or change lands across the fleet at once instead of being edited printer by printer. See the OrcaSlicer CLI reference for automating the engine directly and the PrusaSlicer overview.