The purpose of custom umbrellas is to keep you from getting wet in the rain. You can also use it to shield yourself from the sun's intense heat. They can be held in your hand and are small enough to fit in your bag. The designs that are popular right now are made of polyester or nylon and then coated with Teflon to make them waterproof. Giving away personalized umbrellas at wholesale prices is a great way to get your name out there while people use them. They are very useful and make a good giveaway for a business.