I used a normal sheet of paper. Well, out of a sketch book, but it's the same size nontheless. Yes, it did take quite a while. A little over a day, I might add. Considering I was used a mechanical pencil with .05 sized lead didn't help things go any faster either.
I was just trying to tell how big it was by the size of your pencil strokes. 0.5mm works for fine detail. I would've use a much thicker one for shading. But I don't draw in my free time, usually during lectures at school. I suppose I should try some .hack material some time. But It'd never be as good as yours.