Dogs and carpet do not mix

Gusteau happened to get ahold of a black ink pen and chewed it up. By time I noticed, his whole face was stained black and there was a huge spot on the carpet. I chased him away, only to realize ink was all over his paws and he was trailing it everywhere.

As you can see, I could not get the stain out :(  It is pretty noticeable.

P.S. This happened the first month in my new apartment!