grease pencil jagged lines my Blender produces very jagged lines in 2D Animation mode (grease pencil). It seems to be updating my pens position at a very low framerate. Turning input samples to 10 has no effect. What do? Im ...
i think this will solve your problem. At the Draw menu go to :


Options -> Check Post-processing menu 
Subbdivision Steps (1 -> 3)
(Optional) Smooth (0.1 -> 2)


The quality of the stroke (number of points added which you can see in Edit mode) is inversly proportional to the drawing speed.
Sorry for my English, Hope it helps !