Adobe Illustrator is the leading software for creating vectorized graphics. it has many powerful tools and unique features. Adobe Illustrator brushes and patterns are a lot less around than Photoshop but here you’ll find 65 High-quality Adobe Illustrator Brushes And Pattern Sets, you can add them and use both in personal and commercial projects to enhance your designs and creativity. The best thing about this collection is that they are vectors and can be fully personalized to fulfill all your needs by changing size, colors ect..
Note: Many of the designers offering free but you should also take a look at the licenses, so you could know how you can use them.