Ink on soft leather sofa

[Behooven]

Dh has a habit of nodding off mid crossword, this time he fell asleep with pen in hand with the result of a black biro line on the arm of the sofa.
Any ideas for getting it off without damaging the leather? I have one of these magic eraser thingys but want go be sure there won't be a mark left.

Baby wipes are good for getting ink off leather.

If it's a pale colour of leather, I'd use cif.

I'd try baby wipes first, followed by hairspray.