I have the following ListPlot:
ListPlot[{{1, 3}, {2, 4}, {3, .3}, {4, 6}}, Filling -> Axis,
FillingStyle -> {Thickness[0.008], Black},
LabelStyle -> Directive[20], Frame -> True]

I have a problem with the lines below the points: They are too thin. How to change the Thickness propperly? FillingStyle -> {Thickness[0.008], Black}, seems not to be correct.


DirectivewithFillingStyle, but you don't need it forLabelStyle; i.e.,FillingStyle -> Directive[Thickness[0.008], Black], LabelStyle -> 30will work. – m_goldberg Feb 19 at 16:21