I Am Legend - Smeared Ink Chapter headings . . . is it planned, or a printing error?

Well, it was a design choice. There's an interesting YouTube video about the choices made in illustrating the book.

From the illustrator Dave McKean: "The type just needed something, just needs to be destroyed, desiccated, eaten away a little bit . . .".

(Since I have my answer I tried to delete this entire post, but it appears that it isn't possible to delete the post header. Might be useful to FSDs in the future to have this information.)