Silk is a protein fiber that comes from the cocoons of certain caterpillars.   Silk
is a good charkha fiber because it likes to be spun fine with a high twist.  
However, silk needs to be handled differently than cotton because of its long
staple length.  It is also one of the world's strongest fibers.
Bombyx silk comes from
the bombyx mori
caterpillar, which grows
into a small white moth
that eats only mulberry
leaves.  This is also
sometimes called cultured
silk, it is a very fine,
naturally white silk.

I love spinning this roving,
dyed by my friend
Lorraine.  The colors are
beautiful and it has a glow
to it in the sunlight
Mawata silk is actually a different preparation of
bombyx silk.  Instead of carding the fibers into a
roving, the cocoons are attenuated over a frame in
either a square shape (hankie) or bell shape (cap).

Mawata silk requires a great deal of preparation
and pre-drafting before spinning because instead of
being lined up like in a roving, they are kind of a
mis-mash laid out a lot like they were in the
cocoon.  It makes a really interesting, somewhat
nubby yarn with lots of character.

This particular sample came from a cap.  I was told
the colors would be muddy in the final product
because of the way they were laid out and the fact
that they were not in the same family.  In the
pre-drafting process, I picked where to attenuate
the fibers to try and keep the colors more separate
and was very satisfied with the result.
The caterpillars that make
tussah silk are not as picky as
bombyx caterpillars, they will
eat anything.  Tussah silk is not
as fine as bombyx silk and is
beige in color.

Tussah is the silk I would
recommend to a beginner who
wants to try spinning silk.  It
does not grip up as fast as
bombyx when twist is added, so
the fibers slip past each other a
little better in the drafting
process.  The yarn is a little bit
fuzzier than bombyx, but still