American Painter Long Handled Fan #6 - the one for getting into the hard to reach places for interior coloring on head and limbs.  Also great to spread water based glues inside the head after rooting (be sure to wash well with soap and water!)

These are the Loew-Cornell quality brushes which I use the most and demonstrated in the "Art of Newborning" and "Painting with Genesis" DVDs by Secrist Doll Co.