Oooops I knew I was supposed to be doing something.
Just had a go at using watercolour pencils on a inkjet printed digi image and the ink ran a little bit, I suppose if you had an image that you didnt go over any ink it would be ok, the eyes ran on my digi face.
Staz on is the ink to use if using stamps and watercolouring
Hope this helps.
Fiona x