Simplify3D line width settings, do you match nozzle size or not?

[PowerEllone]

I’m trying to understand line width as a basic setting, but it feels more complicated than it should. I use a standard nozzle, but the slicer still lets me set line width to a range of values, and I don’t know what the safe range really is. I keep hearing it depends on the nozzle and filament and flow, and I would love a simple rule that works most of the time.

This weekend I printed a simple bracket and changed nothing except line width. One setting gave me clean walls and it was satisfying because it looked stronger and more consistent. Another setting gave me little gaps between lines, and then another one gave me bulging corners like it was overstuffed. If you had to explain line width in plain terms, when is it okay to go wider than the nozzle, when should you go narrower, and what problems show up first when you push it too far?

 

[Alan]

What nozzle size and filament are you using in Simplify3D, and is this PLA, PETG, or something else. Also, are you printing in a drafty room or near a window, because winter air can exaggerate under extrusion and those little gaps you saw.

 

[KingCarnelian]

The way you described it makes sense. Too narrow tends to show gaps and weak looking walls first, too wide starts looking overstuffed with bulging corners and messy edges. For a standard nozzle, I’d keep the range tight and use small changes, then confirm with a simple wall test so you know it’s real and not just one model.