how do we get ink off DS's fingers please?

[mckenzie]

DS (9) has started to use an ink pen at school. It does seem to be helping his handwriting to improve but it is all over his fingers. Two baths later and it's still there! Any tips please?

TIA

I got food colouring that wouldn't shift of my ds with bicarb of soda. It might work with ink?

worth a try ftg, off to have a go.