How to Keep Hair Straight - People with naturally curly hair often straighten it via a variety of different means. While chemical straightening treatments permanently straighten treated hair, most other straightening processes are temporary. If you straighten your hair with a blow dryer and straightening iron, it will curl back up once the hair gets wet. Various environmental factors such as humidity and fog can keep hair from remaining straight. If you have straightened your curly hair, there are a few things you can do to keep it straight. Things You'll Need: Straightening shampoo Straightening conditioner Straightening iron Silicone-based pomade or serum Hairspray Grated coconut Lime juice Instructions Keep your hair long. Shorter hairstyles tend to curl up more quickly. The added weight of longer hair can keep it straighter longer. ...