My "perfect" carbon-look build plate settings  

My "perfect" carbon-look build plate settings

Dear Prusa Forum,

after fiddling around with the new possibilities of the Core One, coming from an mk3s, I've found my "perfect" settings for printing rather small projects on my carbon-look print sheet.
I've attached a photo, an example project and going to list the important settings.

Settings:

1. Bed temperature: for 1st layer about +7°C to make the filament flow better into the carbon look pattern and into itself.
2. Higher nozzle temp: for 1st layer until it becomes too messy. The photo shows Sunlu PLA matte black, which lists 190°-230°C on the spool. I've used 237°C. Rest of the print at 212°C.
3. Z-Offset: to -0.05 to squish the filament into the print sheet and into the already laid down lines.
4. Reduced 1st layer speeds: First layer speed + infill speed set to 10 mm/s. You might be able to go a bit higher, but the extruder gear started clicking due to the backpressure at the tip of the nozzle.
5. Smaller extrusion width for 1st layer: 0.22 mm. Basically, a setting for "Infill lines overlapping %" would be needed. But instead, a smaller extrusion with, combined with a higher flow rate does the same.
6. Higher flow rate for 1st layer: Now a bit more complicated.. PrusaSlicer -> expert mode -> Settings -> Printers -> Custom G-code -> Start G-code. Last line: Change the M221 S100 command to: "M221 S128 ; set flow to 128% for matte filament on Carbon Look Sheet".
   All settings combined lead to a really ugly surface at the top of the 1st layer, which requires the 2nd layer to have a reduced flow rate, to then go back to 100% from the 3rd layer onwards.
   So the "Before layer change G-code" needs these two lines:
   {if layer_num == 1}M221 S95 ; Reduced flow rate to counter overextrusion during 1st layer{endif}
   {if layer_num == 2}M221 S100 ; Reset flow rate to 100% from second layer on{endif}
7. Important: 1st layer infill pattern = Hilbert Curve: This quite special combination of settings won't work with most infill patterns. Monotonic will just squish the lines into an ugly, wavy pattern. Hilbert Curve, however, basically "tattoos" the filament onto the print sheet.
8. Reduced heatbreak target temperature: The backpressure on the nozzle tip is pretty high and due to the slow filament speed, the filament in the extruder gear might become too soft. 
   PrusaSlicer -> Settings -> Filaments -> Custom G-code -> Start G-code. Last line. "M142 S36 ; set heatbreak target temp" should be adjusted to "M142 S32 ; set heatbreak target temp"
9. Fuzzy Skin: Set to none, then painted it on with smart-fill. Thickness = 0.07 mm, point distance = 0.1 mm

Another important point:
Activate the heatbreak temperature reading for the footer:
Core One display -> Settings -> User Interface -> Footer -> empty slot = "heatbreak".
My extruder started clicking, when the heatbreak temperature went above 37°C. Even with the chamber fans set to 70%, the heatbreak fan just didn't get enough "cold" air. Leaving the fans at default and simply opening the door a little bit was enough, combined with the reduced heatbreak target temp.

I'll try to get a similar look with the 0.4 mm nozzle, but I can't get the fuzzy skin looking as good, as with the small nozzle, so it had no priority yet.

Hopefully, this might help a few people to get a nicer carbon look 🙂

Disclaimer: I've adjusted a lot of settings in the slicer, that aren't important for this specific look. Like adjusting the limits for stealth mode, all speeds etc. to quiet down the Core One.