Multiple extruders

If you have a dual (or even more than two) extruder setup, Slic3r can be used in two ways:

• you can print a normal single-material object by assigning different features to different extruders: for example perimeter/infill/support material;
• you can print a multi-material object by assigning each material to an extruder

First step: configure your extruders

Open the Printer Settings tab, then open the General section and look under Capabilities. Set the Extruders option to the number of extruders your machine has.

Then open the Extruder 1 section on the left and configure the nozzle diameter. Go on with Extruder 2: this time you may want to configure the offset too. This should contain the positive distance from the first extruder's position (this is why you leave this at 0,0 for the first one). If your firmware knows about the extruders' offsets and takes them into account automatically, leave every offset at 0,0 in Slic3r.