Hello! I'm pretty new to the Cura software and I was trying to read and understand the G-Code for some modifications I need to do. Basically I want to chance the inner filler of a sliced part but keep it's outer filling but I'm unsure of which part is it, reading through the G-Code I noticed we have SKIRT, WALL OUTER, WALL INNER and so on,, some of then appearing more than once, my question is, which part is responsable for the outside of a part? And which for the inside? If I only want to alter the inside where should I write?