The picture below is an experiment I did on prewashed
muslin using Derwent Inktense Pencils.  The ink is permanent
when it dries on paper, but I wanted to experiment on fabric.  
On the first hand I used floating medium with the Inktense
pencils, the second hand I used Aloe Vera gel with the
pencils, the third hand I used a 50/50 mixture of Aloe Vera gel
and textile medium with the pencils and finally on the fourth
hand I used textile medium with the pencils.  I heat set all four
hands.  Then I took the muslin to the sink and let the fabric
soak in cool water.  No bleeding occured on any of the
experiments!!  The textile medium left the fabric a little stiffer.  
I'm so impressed with Derwent's Inktense Pencils ♥