There are many different pieces of clothing you can put motorcycle patches on. Many people add them to their jackets because they're the most visible, some bikers can also put patches on their vests. While not all motorcycle riders wear vests, many do. Any patch you wear on a jacket can be attached to a vest, too. This means you can wear a patch-covered vest under your jacket if you want and show off two sets of patches, but many bikers wear one or the other. If you live in an area that is warm all year round, you might not want to wear a jacket. A vest, especially a sturdy leather one, can help protect you if you crash while keeping you from overheating.
The one drawback to wearing a vest instead of a jacket is that vests don't have quite as much room for patches. Since they don't have sleeves, you won't be able to put rocker patches on them like you would with a jacket. You can put rockers on the front of the vest, of course, and many people do. You can also put large patches on the back of your vest and plenty of small patches on the back and front.
If you don't often wear a jacket or want something to wear when it's warm outside, a vest is a great piece of biker gear that you can cover in patches. Vests come in all sizes and in many colors, too, so you can pick the one that best fits your style. No biker should be without at least one leather vest in his or her wardrobe. They're one of the essential pieces of biker gear.