Dove Blender Pen (http://store.scrapbook.com/dovblenrefpe.html) is a must tool for me. So I bought this refill and replacement tips(http://store.scrapbook.com/dovblenrepti.html).
This pen can easy to get fabulous effect for coloring images with crayons (polychromos pencils is also available) , watercolor pencils, chalks ,etc.
Chalk square dose not need to be sprayed to be permanent.
And this is so useful for picking up color from an ink pad.
This blender pen is so useful, I think.