Do not judge a book by its cover.
- English idiom
책을 겉표지로 판단하지 말라
- 영어 속담
http://en.wikipedia.org/wiki/Don't_judge_a_book_by_its_cover
"Don't Judge A Book By Its Cover" at GoEnglish.com (with illustration)
You Can't Judge a Book by Its Cover (Desperate Housewives)