Adding text that's not embossed but flat?  

Best Answer by JoanTabb:

Hi Kivroth, 
one way is to use virtual extruders
I am assuming that you are using PLA  (If not, change the filament type in prusa slicer and start the print with that type pf filament in the extruder...)
basically tell the Slicer that the printer has two extruders, 
in the example provided 
I created an Oval, 3mm thick, and then added the text using  it as a modifier rather than an additional part
I adjusted the text height  until the text was large enough, and changed the thickness to 0.4mm (two layers at 0.2mm layer height)
this gave me two items in the right hand slicer window
I allocated the main body, to extruder 1 
and I changed the extruder for the modifier text to extruder 2.
This resulted in an orange oval with Black text in Prusa slicer (in reality the printer hasn't got a clue what colour the filaments are)
so start the print with any colour PLA  in the extruder, because when you use this method, the printer does mesh bed levelling and the prime line, then immediately requests a filament change, at this stage, put the main body colour into the extruder. 
the printer will print up to the layer where the colour change needs to occur, and it will print all of the parts that are not colour two, 
then the printer will request a filament change (colour change), and print two layers of text, then it will request another filament  change, and print the surrounding elements on the top layer. 

In prusa slicer print settings layers and perimeters, I have told the slicer to only use one perimeter on all top layers, this should give the best lettering possible

when adding lettering it is usually best to use a 'san serif' font like Arial  (Large text can get away with fancy fonts but smaller text struggles with the infill in fancy fonts. ) 
I normally turn off the purge tower, but some folk like the purge tower. so I have left it on for the time being

during filament changes the printer normally moves the extruder to the front right hand side of the build plate, and then asks you to remove the current filament,
then it asks you to insert the next filament, and it purges some filament to clear the old filament out of the nozzle, then it asks you if the filament is clear (in other words is the filament showing the new colour, lets assume the answer is Yes, RESIST THE TEMPTATION TO PULL THE WASTE MATERIAL OFF T|HE NOZZLE instead, hold the waste with a pair of tweezers, or long nosed pliers and then click the LCD control to continue... 
the printer will squirt another length of filament out as it moves back to the print, and this will remain stuck to the waste that you are holding, and pull off the nozzle. 

Please note! all of the above work was done with Prusa slicer in Expert Mode, so that all options are available.

Below is a zip compressed project file, for this project. 
If you download the file, unzip the file to create a .3mf file, then you can open the project file, from the files menu, open project, option. 

this should import all of the settings into your prusa slicer session. 
Kivroth

regards Joan