OrcaSlicer: add a pause and swap filament colors

Setting the pause in OrcaSlicer

1. 1

   One-time check: the pause command

   Click the edit icon beside your printer to open its settings. Under Machine G-code, find Pause G-code. If it's blank, copy the right command from the table below, because a blank box means no stop.

2. 2

   Slice it once

   Hit Slice plate. You land on the Preview tab, with a tall layer slider down the right side.

3. 3

   Scroll up to the color change

   Slide the top handle upward until you reach the lowest layer that has only the second color in it. On a name sign, that's usually where the letters start rising off the base. The slider's label gives you two numbers: the layer and its height in mm.

4. 4

   Drop in the pause

   Right-click the handle marked + and pick Add Pause. A small marker shows up on that layer, and the printer will stop right before it begins.

5. 5

   Re-slice and send it

   The pause makes the old slice stale, so press Slice plate one more time. Then print or export the way you normally do.

Which layer, though? The first one in the new color. Here's how to spot it.

Your printer's stop command

Each firmware listens for its own command. These are the ones OrcaSlicer's built-in profiles put in Pause G-code:

When the printer stops

Load your first color and start the print. Once it reaches the pause:

1. 6

   The printer stops

   It completes the layer below and halts. On most firmware the toolhead parks off to one side.

2. 7

   Change the spool

   If your printer uses M600, it unloads by itself and prompts you for the next spool. For PAUSE, M601, M0, or M25 you do it from the screen's filament menu: heat up, unload, and load the second color. Purge until it runs clean.

3. 8

   Carry on

   Pick off the purged string, keeping clear of the print, and choose Resume on the printer.

Changed your mind? Taking the pause out

Slide back to the layer with the marker and click the × that sits next to the handle. (A right-click on the handle also offers Delete Pause.) Slice once more afterward.

Things that trip people up

• Printer never stopped? Look at Printer settings → Machine G-code → Pause G-code. When that box is blank, the slicer leaves only a note in the file and the printer carries straight on.
• Own a MK4S? In OrcaSlicer, its Prusa profiles carry over Bambu's M400 U1 for the pause. Put M601 in Pause G-code instead (or M600 if you want the guided version).
• With one nozzle, choose Add Pause, not Change Filament. The filament change route runs through the tool-change G-code, and people have reported it kicking in partway through a layer and leaving blobs.
• Can't click Add Pause? The print sequence is probably set to By object. Change it to By layer under the process settings and the option comes back.
• Don't pause in the first 2 or 3 layers. A thin print waiting that close to the bed can cool off and peel up.

Quick answers

OrcaSlicer added my pause, but the printer kept going. What happened?

Nearly always a blank Pause G-code in the printer profile, which leaves nothing but a comment in the file. Open Printer settings > Machine G-code > Pause G-code and type the command your firmware uses (Klipper takes PAUSE, Marlin takes M600 or M0, Prusa takes M601). Slice again after.

My printer runs Klipper. Will M600 work?

Only when the manufacturer included an M600 macro, so PAUSE is the safe pick. Prusa printers, and Marlin printers built with the advanced pause feature, do understand M600, and it guides you through the unload and reload.