I've just posted a picture of a scarf I hand painted last summer.  It is 100% silk and the process I used was very simple.  You do have to use special paints made just for silk.  Otherwise its a snap.  Wet the scarf, paint and let it sit covered with plastic wrap for 24 hours.  When you take it out you will be very surprised at how the paint has spread and made your wonderful 'picture'. 

 This one I named 'waterlilies' and its the first one I did.  I have another one not finished but will post the picture at a later date.

This one below a friend did and I remembered to take a picture while she was doing it.  The pic on the left is right after she finished.  It is still wet and in the tub with the plastic wrap covering the top.  After it set for 24-hours, it was rinsed in cold water, hung to semi-dry, then ironed to get the silky shine back into the fabric.  I think hers turned out just beautiful!

Her colors were so much more vivid than mine and she used a little more paint.  I think I am going to try that the next time I paint one.