Each pastry tip (nozzle) has a precise function and design. Plain tips have a round end that will let you pipe puffs or macarons (macaroons), for instance. Fluted or star tips have a serrated end that can be used to pipe whipped cream over a fruit salad or to decorate a cake. Tips designed for filling are thin and slender, making it easier to fill puffs or éclairs. These tips are the most commonly known and used by the general public. For individuals in the know and professionals, there are pastry tips for making more complex creations. The flat and serrated end (6–8 teeth) of the yule log tip is designed for frosting yule logs. The Saint Honoré tip has an indented end, giving the particular shape to the Chantilly cream decorating this pastry made up of puffs. The “sultane” piping tip is designed for decorating religieuses with Chantilly cream. The bird nest or vermicelli tip will let you make decorations in the form of strings, thanks to its flat, perforated end, while a leaf tip will let you make leaf-shape decorations. You can also find pastry tips for making flowers, roses, petals, or braided decorations. All of these tips come in different sizes. The diameter of plain tips, for example, can range between 3 mm and 20 mm. Certain tips are made from stainless steel, while others are made from polycarbonate, a clear, unbreakable material that keeps its shape, and which lets you see if there are air bubbles inside the tip.