A method of applying a label (12) to an article (10), the method comprising : - providing an article having a surface comprising at least one compound curve (16); - providing a label comprising (i) a heat shrinkable film having an inner surface and an outer surface; and (ii) a layer of pressure sensitive adhesive on the inner surface of the heat shrinkable film, wherein the label has a first edge and a contact region,- - contacting the adhesive layer in the contact region of the label with the article; - and applying heat and pressure simultaneously to the label in a direction from the contact region to the first edge such that the first edge of the label adheres to the article and the label shrinks to conform to the compound curve of the article, wherein the heat and pressure are applied by at least one hot air knife assembly comprising a source of heated air, a flow control mechanism and one or more hot air slots.