Interesting, though from what I can find online, the puff paint's lines don't look quite as smooth and molded as the ones in the poster. Although I guess I can buy the "bit of ingenuity" thing better here than I can with Maguire, because this Peter Parker is more clearly a gifted inventor and scientist than his screen predecessor.
From what I've seen, the puff-paint results can vary based on how steady the artist's hand is. The really good stuff done by professional seamstresses is crisp. Parker's got super-human coordination in addition to being ingenious, so I have no problem handwaiving away that he could do even better than that. It's spider-powers, baby.