A number of years ago, my youngest son was studying in Vienna.  For my birthday, he bought a handsome landscape done with palette knives.  That became the spark for an effort to paint with palette knives.
 
This may be the penultimate painting experience for me.  It is the tactile feeling of holding the knife, pulling the paint across the canvas, and literally working with a large amount of paint.  It is also a challenge because it has to essentially be finished on the first pass, the rugged surface does not allow any reworking at a later time.