"P e n" a n d "I n k"

I am what they call a pen
you all know me by name
Calli and Graphy use me to write
but first they cut me up to size
the style in which I write depends
on the angle and thickness of my end. (nib)

Beautiful looking bottle am I
full of ink
of every style
to write they all (brushes & pens)
must dip in me
to show the world
their creativity.