Från och med första gången introducerades Harry (och vi) i kappan
This only left one parcel. Harry picked it up and felt it. It was very light. He unwrapped it. Something fluid and silvery gray went slithering to the floor where it lay in gleaming folds. Ron gasped. "I've heard of those," he said in a hushed voice, dropping the box of Every Flavor Beans he'd gotten from Hermione. "If that's what I think it is -- they're really rare, and really valuable." "What is it?" Harry picked the shining, silvery cloth off the floor. It was strange to the touch, like water woven into material. "It's an invisibility cloak," said Ron, a look of awe on his face. "I'm sure it is -- try it on."
JKR håller hela beskrivningen genom böckerna. Så du kan definitivt se det (det verkar också att känna sig annorlunda än normalt material).