Just thought i'd stick this in while I'm on a roll here. It's just an email between me and Shaun Tan from my foundation year. It was from when i first saw his artwork, and my favourite piece of his intrigued me so much i thought i'd just go out there and ask. This was a decision i made off my own back, and i didn't think i was even going to get a response since he's been involved in films like Wall-e, so was pretty excited when he replied. This will give me the confidence to contact future illustrators.
Thanks for the email. Unfortunately, I don't have much time these days to comment on student's work or offer advice about technique, colour or composition. Of Grandpa's Story, I can briefly say that the medium used here is a cheap, fine-tip ballpoint pen, over ink and thin gouache washes, on watercolour paper. The effect is a bit like etching, but far simpler, and not very technical. As far as other tips, the best I can do is just point to the images themselves - all answers are there :)
Good luck with your diploma!