¶ Description
This setting directly adjusts how much material is placed down. Normally the amount of material is calculated by Snapmaker Luban such that the material would fill the exact space in the line's width, height and length, but this can be adjusted using the flow settings.
¶ Usage
The main use case for this setting is to compensate for some fault during extrusion. For instance, if the nozzle is slightly clogged, underextrusion will occur. Increasing the flow could then push more material through the clogged nozzle, hopefully causing it to end at the right amount of material. This can also compensate for slip or variance in filament diameter.
It is almost always better to fix the actual problem causing the overextrusion or underextrusion, but adjusting the flow can be an easy temporary fix.
If you want the lines to be wider, it is better to adjust the actual line width setting. The line width doesn't necessarily need to be the same as the nozzle size. Adjusting the line width will also adjust the spacing between the lines which prevents overextrusion and underextrusion. Adjusting the flow doesn't adjust spacing.