A "star tip" is a type of decorating nozzle used in cake decorating and pastry work. It has a star-shaped opening that creates a textured design when icing or frosting is piped through it. Star tips come in various sizes, allowing for different effects, from small, delicate rosettes to larger, more pronounced decorations. These tips are commonly used with piping bags to create borders, flowers, and other decorative elements on cakes and cupcakes. They are often made of stainless steel or plastic and can be easily cleaned and reused. Popular brands include Wilton and Ateco.