[CkChRIzZ]

of course it is.
it's pretty simple too.
just click in one area of the canvas, then click in another, then click in the middle on that line, hold ctrl and drag the point you just made in the middle of the line. there's one curve.
then just keep clicking and dragging until you have as many curves as you want.
and for lines to be getting thicker and thinner you just have to check the 'stimulate pressure' box when you right click on the line and select stroke path.
make the ends longer though because when you use stimulate pressure it never reaches to the actual end of your pentool line.