Katy, 26, says she takes the blanket on tour with her because it reminds her of home.
She said, “I have a little pink blanket that I snuggle into at night and I have a dressing gown from home.
“That’s me at my most comfortable and private on the bus.
“No-one should ever see me in that state.
“I am not trying to ruin anyone’s idea or dreams of me!”
She also said she sometimes takes one of her and husband Russell Brand’s pet cats in first class with her when she flies.
“That was a pretty weird request, to put a cat on a plane and bring her across.
“She goes first class, but under the seat.
“She doesn’t get her own seat,” she said.