G-Code for filament retraction

[iras]

Hi,Whenever I finish a print and go back and start another print, some filament oozes out of the nozzle while the extruder is pre-heating. Once pre-heating is done, I wipe it off, but I have to watch and be sure to do this or the string of filament winds up as part of the print somewhere.I'd like to add a command in Slic3r's Printer Settings, Custom G-Code, End G-Code to retract the filament 3mm or so automatically at the end of each print. On my previous printer that seemed to take care of the problem. And, given that the Prusa MK3 (my printer) does an initial extrude strip to insure filament is flowing, the retraction won't hurt anything. Can someone tell me what the G-Code would be to retract 3mm of filament (relative). Thanks.

[printbus]

FWIW, here's part of my end script from Simplify3D for my Wades extruder -

M83 ; extruder to relative
G1 E-2 F900 ; retract 2mm at 15 mm/sec

[iras]

Thanks. I'll try it - looks good.