She told website fashionista.com: "I was wildly intimated. He's an incredibly intimidating person because he's so accomplished and he's such a genius, but the moment you meet him, he doesn't try to intimidate you. He's so kind and humble and alive and passionate. I love and respect him so much."
However, the 23-year-old beauty also confessed she would not want to work with any other design house.
She said: "I wouldn't want to work with anyone else. The moment I met him I said, 'I don't want to do a campaign unless it's Chanel'. So it's nice that we get to work together."
Blake also confessed she was hoping to see all of the collection ahead of the show's Paris Fashion Week display this weekend.
She said: "I'm going to Paris this weekend for the dinner. I'm thrilled. And hopefully Karl will give me a sneak peek of the show beforehand. I love seeing the pieces in person."