Also known as roasting bags, oven bags are suitable for cooking foods in the oven up to temperatures of gas mark 8, 230°C. They help to seal in the natural juices and moisture of food and also keep the oven clean. They are made from high-quality polyester. Simply place the food to be cooked in the bag, cut off a corner to let out excessive steam and place in the oven. Oven bags can also be used in the microwave and freezer.