Very Good
I'm very happy with this product.  My toddler daughter is trying to emulate her parents and write with a fountain pen.  Its great watching her develop, however the mess that she makes can sometimes be a challenge!  This ink is very washable and is allowing us to both have fun.  There is a slight red hue left after the initial rinse but that is quickly removed with a little soap and light scrubbing.  It came off our hands, cloths, floor..etc.  The ink itself flows well, and doesn't cause staining that we have noticed.  There is very little feathering.  If I were to have any constructive criticism it's in he lubricity of the ink.  The pen feels a tad more scratchy using this ink than others, but that is a minor tradeoff considering its advantages.  Great product overall.
Rating: 5 stars