Uni-ball Hi-Uni Hi-Density Pencil Lead - 0.3 mm - 2H

Not a lot of love is given to a 2H lead, but this is remarkably smooth for a 2H. First, it is very break resistant (in a cheapish plastic Staedtler 925).

It's capable of some very fine lines, so it's perfect for super-small writing (compact notes, for example). With harder leads, the less tooth the paper has, the better. For notes like in a Bible or other book with similarly high quality paper, it's excellent.

It's also very erasable, so if you are doing a preliminary sketch, it's a good choice.

For the ultimate in fine lines, I would recommend this lead in a Uni-Ball Kuru Toga pencil.