Help needed

I don't know.........

hey hi,

it means darkest black color as possible which should not have mixture of either dark brown or blue with in.

thanks

hi vaibhav can i used black gel pen

hi since they have mentioned only pen, yes. But you should make sure that it should not spread across, so indeed it should be water proof.

I would suggest a jet balck pen (Roller ball pen), as you don;t know how the paper quality would be, also, an ink pen has a chance of smearing of the ink on the paper.