One day when I was studying with
Schoenberg, he pointed out
the eraser on his pencil and said,
“This end is more important
than the other.” After twenty years
I learned to write directly in ink.
Recently,
when David Tudor returned from Europe,
he brought me a German
pencil of modern make.
It can carry any size of
lead. Pressure on
a shaft at the end of the holder
frees the lead so that it
can be retracted or extended or
removed and another put in its
place. A sharpener
came with the pencil.
The sharpener offers not one
but several possibilities.
That is,
one may choose the kind of point
he wishes.
There is no eraser.
Source: lcdf.org