If I manage to become a rich and famous cartoonist, or at least a commercially viable one, the first assistant I hire will be someone to do the erasing. Make no mistake, erasing takes skill and patience. I don't discount the need for a responsible person. I just get sick of dealing with the eraser crumbs. During extensive erasing, even a kneaded gray eraser will shed some little rolls of eraser cheese. And some stuff just needs to be gone after with the white Magic Rub. That thing sheds like the cats.