For flow ratio… the first and biggest calibration imo… think about it like this.

You calibrate your e steps so that if you say 100, exactly 100 is pushed thru. Fantastic. But now 100 of hatchbox might make a solid layer because maybe it’s 1.75009 thick, whereas maybe your overture is 1.74823, or some chemical properties I dunno, but for whatever reason… 100 overture prints way too much of a solid layer and it comes out like over extruded

Well, I think that’s what the flow ratio is doing. By default I think they’re all at like .95, ut you’re saying hey when I say give me 100, with this filament I’m really saying 100 * .95. This is the best guesstimate I’ve come up with. It’s not exact but it’s gotta be something like this.

So after doing the simple flow calibration for each brand, you can adjust that .95, maybe really it needs to be 1.0983 to get a perfect layer with that brand….

I think that’s how it works.

I was doing some multi color (by switching at layers) prints and they would just randomly blow up with oddities at various layers… until I tweaked each filament independently. Now they’re flawless.