It looks like Prusaslicer can't do Multiple Materials!  

RE: It looks like Prusaslicer can't do Multiple Materials!

If you have set things up correctly, the right hand pane will have one drop down menu for each extruder from which you can select the filament

RE: It looks like Prusaslicer can't do Multiple Materials!

Ok… I see now. The filament tab is actually a Filaments tab and it’s all your filaments not just for the Print.

RE: It looks like Prusaslicer can't do Multiple Materials!

One other caveat, those drop downs pull their settings from SAVED filament profiles. If you make changes to stuff on the filament profile tab it does not get used by the print when you slice , until the change is saved to the profile. 

This functionality is different when you only have a single extruder as changes made to the single profile get reflected in the slice (you can see the name in the drop down change to have modified after it). 

RE: It looks like Prusaslicer can't do Multiple Materials!

I went back in and looked again. Sorry... I'm not getting it at all! There's nothing that I can see that says Add new material. If I switch from PLA to PET than that item in the menu becomes a different material and it's the same item in the menus elsewhere. I would expect to see something that lets me Add to that pull down list. Where is that?

RE:

Same places where you can add other filaments.  One is to run the configuration wizard again and add filaments from Prusa's list you may have skipped the first time around. To add your own, go to the Filament Settings Tab (Ctrl-3/Cmd-3). Start with something close, make your adjustments, then click on the little floppy disk icon next to the filament name and give it a new name. It'll show up in the dropdowns on the main screen under User Presets.

RE: It looks like Prusaslicer can't do Multiple Materials!

OK... I see now... you can change the text in the field.